BACKGROUND
Field

Implementations described herein generally relate to methods and apparatus for polishing substrates, more particularly, to methods and apparatus for identifying and/or tracking movement of a polishing material in a roll-to-roll polishing system during processing.

Description of the Related Art

Chemical mechanical polishing (CMP) is a conventional process used in many different industries to planarize surfaces of substrates. In the semiconductor industry, uniformity of polishing and planarization has become increasingly important as device feature sizes continue to decrease. During a CMP process, a substrate, such as a silicon wafer, is mounted on a carrier head with the device surface placed against a moving polishing pad. The carrier head provides a controllable load on the substrate to push the device surface of the substrate against the moving polishing pad. A polishing slurry, including an abrasive and at least one chemically reactive agent, is typically supplied to the moving polishing pad to provide an abrasive chemical solution at the interface between the pad and the substrate. The polishing pad and the carrier head apply mechanical energy to the substrate, while the pad also helps to control the transport of slurry, which interacts with the substrate during the polishing process.

An effective CMP process not only provides a high polishing rate, but also provides a substrate surface which lacks small-scale roughness, contains minimal defects and is flat, i.e., lacks large scale topography. In addition, an effective CMP process also provides consistent polishing results or “repeatability” between substrates in a batch (e.g., 25 substrates). Polishing a substrate with uncontrolled, misaligned or improperly positioned polishing material relative to the carrier head and substrate can adversely affect the process results and process repeatability between substrates within a batch, which affects device yield.

Issues with the proper positioning of a desirable portion of a polishing pad relative to each processed substrate is increasingly important when the pad is not fixed, and is indexable, relative to the platen that the pad is positioned over, such as found in roll-to-roll polishing pad configurations. Moreover, the accuracy of placement of the polishing material relative to the substrate and the carrier head can affect the cost to produce semiconductor devices and the cost of ownership of a semiconductor device production line.

Therefore, there is a need for an improved apparatus and methods for identifying and/or tracking movement of a polishing material in a roll-to-roll polishing system that address some of the aforementioned concerns.

SUMMARY

Implementations described herein generally relate to methods and apparatus for polishing substrates, more particularly, to methods and apparatus for identifying and/or tracking polishing material in a roll-to-roll polishing system. In one implementation, an apparatus for polishing a substrate is provided. The apparatus comprises a polishing module. The polishing module comprises a platen for supporting a polishing material having a polishing surface and an opposing backside surface, wherein the backside surface has a plurality of identifying features formed thereon. The polishing module further comprises a supply assembly that is adapted to provide the polishing material to the platen and a take-up assembly that is adapted to receive the polishing material transferred across at least a portion of the platen from the supply assembly. The apparatus further comprises one or more detector assemblies disposed adjacent to the backside surface of the polishing material. The one or more detector assemblies are positioned to sense a change in position of the plurality of identifying features formed on the backside surface as the polishing material is transferred between the supply assembly and the take-up assembly. The apparatus further comprises a system controller adapted to receive a signal from the one or more detector assemblies and control the position of the polishing material relative to the platen using an actuator coupled to at least one of the supply assembly and the take-up assembly.

In another implementation, a method of polishing a substrate is provided. The method comprises advancing a polishing material across a surface of a platen. The polishing material has a polishing surface and an opposing backside surface and the backside surface has a pattern of identifying features formed thereon. The method further comprises sensing the movement of the pattern of identifying features past a detector assembly. The method further comprises controlling a position of the polishing material relative to the platen based on data received from the sensed movement of the pattern of identifying features.

In yet another implementation, a polishing article is provided. The polishing article comprises a linear polymeric sheet having a length that extends in a first direction. The linear polymeric sheet has a backside surface having a plurality of identifying features formed in an array extending in the first direction thereon. The linear polymeric sheet has an opposing polishing surface having a plurality of polishing features selected from at least one of a plurality of discrete elements formed in the polishing surface and extending upward from the polishing surface and a plurality of grooves extending from the polishing surface toward the backside surface. At least one of the plurality of identifying features is positioned a first distance in the first direction from at least one of the plurality of polishing features, and the plurality of identifying features are each configured to interact with electromagnetic radiation provided from a source.

In yet another implementation, an apparatus for polishing a substrate is provided. The apparatus comprises a polishing module. The polishing module comprises a polishing material having a polishing surface and an opposing backside surface. The backside surface has a plurality of identifying features formed thereon. The polishing module further includes a platen for supporting the polishing material, a supply assembly that is adapted to provide the polishing material to the platen, and a take-up assembly that is adapted to receive the polishing material transferred across at least a portion of the platen from the supply assembly. The apparatus further comprises one or more detector assemblies disposed adjacent to the backside surface of the polishing material. The one or more detector assemblies are positioned to sense a change in position of the plurality of identifying features formed on the backside surface as the polishing material is transferred between the supply assembly and the take-up assembly. The apparatus further comprises a system controller adapted to receive a signal from the one or more detector assemblies and control the position of the polishing material relative to the platen using an actuator coupled to at least one of the supply assembly and the take-up assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the present disclosure can be understood in detail, a more particular description of the implementations, briefly summarized above, may be had by reference to implementations, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical implementations of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective implementations.

FIG. 1 is a plan view of one example of a chemical mechanical polishing module according to one or more implementations disclosed herein;

FIG. 2 is a schematic sectional view of one example processing station of the module of FIG. 1 taken along line 2-2, according to one or more implementations disclosed herein;

FIG. 3 is an enlarged schematic side view of one implementation of a portion of an advanced polishing article having identifying feature(s), according to one or more implementations of the present disclosure;

FIG. 4 is a schematic top view of a portion of a roll-to-roll type of an advanced polishing article having a polishing surface with grooves formed therein, according to one or more implementations of the present disclosure;

FIG. 5 is a close up isometric view of a portion of a backside surface of an advanced polishing article having an identifying feature(s) formed thereon according to one or more implementations of the present disclosure;

FIG. 6A is a schematic sectional view of the processing station of FIG. 2 having one implementation of a detector assembly positioned therein, according to one or more implementations disclosed herein; and

FIG. 6B is a schematic sectional view of the processing station of FIG. 2 having another implementation of a detector assembly positioned therein, according to one or more implementations disclosed herein;

FIG. 7 is a flow chart depicting one example of a method of polishing with an advanced polishing article having identifying feature(s) according to one or more implementations described herein; and

FIG. 8 is a flow chart depicting another example of a method of polishing with an advanced polishing article having identifying feature(s) according to one or more implementations described herein.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one implementation may be beneficially incorporated in other implementations without further recitation.

DETAILED DESCRIPTION

The following disclosure describes methods and apparatus for identifying and/or tracking movement of a polishing material in a roll-to-roll polishing system. Certain details are set forth in the following description and in FIGS. 1-8 to provide a thorough understanding of various implementations of the disclosure. Other details describing well-known structures and systems often associated with polishing processes and roll-to-roll systems are not set forth in the following disclosure to avoid unnecessarily obscuring the description of the various implementations.

Many of the details, dimensions, angles and other features shown in the Figures are merely illustrative of particular implementations. Accordingly, other implementations can have other details, components, dimensions, angles and features without departing from the spirit or scope of the present disclosure. In addition, further implementations of the disclosure can be practiced without several of the details described below.

As described herein, roll-to-roll polishing systems may be used to polish a surface of a substrate. Typically, the polishing material is wound around spools. As further described herein, in some implementations, polishing pad material is supplied by a supply roll and routed to a take-up roll. The polishing pad material is typically tensioned between the supply roll and the take-up roll, which may provide a tension force to polish the substrate. In some implementations, after polishing one or more substrates, the polishing pad material is advanced to expose an unused or fresh portion of the polishing pad material, which is used to polish additional substrates. As described herein, in some implementations, polishing pad material has a pattern of precisely formed polishing features for removing material from the surface of the polished substrate. These features may include, for example, at least one of grooves formed in the polishing surface and discrete features (e.g., embossed regions, reliefs, pillars, etc.) that extend above or upward from a lower portion of the polishing surface. Since effective CMP processes provide consistent polishing results or “repeatability” between substrates in a lot or batch it is desirable to expose each substrate to polishing material having similar or substantially similar pattern of polishing features to produce similar or substantially similar polishing results. Therefore, it is desirable to know the precise position of the polishing material, and more particularly the precise positioning of the features formed in the polishing material relative to each of the substrates to be polished as the polishing pad position, relative to the polishing platen that it is disposed over, is adjusted during processing.

One potential solution for tracking polishing material in a roll-to-roll system involves the use of a motor encoder to track advancement of the polishing pad. However, use of a motor encoder adds mechanical complexity to the polishing system, which can lead to particle generation within the system. Additionally, the motor's rotational position sensed by the motor encoder is difficult to correlate to the position of the features formed on the polishing pad, since the amount of linear movement of the polishing pad relative to the platen changes as the diameter of the feed and take-up rolls change as the polishing pad is adjusted during processing. The polishing pad will typically stretch when a desired tension is applied to the polishing pad during a polishing process, and the motor is typically not directly coupled to the pad material so that relative motion (e.g., slippage) can occur between the pad material and the output of the motor. In addition, CMP is performed in a wet environment meaning that the motor encoder must be protected from polishing fluids, which adds additional complexity to the polishing system. Further, in a motor encoder-based tracking system if contact with the polishing material is lost (e.g., slippage), the position of the polishing material relative to the platen and the carrier head is lost. Polishing a substrate with misaligned or improperly positioned polishing material can adversely affect repeatability between substrates, which affects device yield. Moreover, the accuracy of placement of the polishing material relative to the substrate can affect the cost to produce semiconductor devices and the cost of ownership of a semiconductor device production line.

In some implementations, the present disclosure provides apparatus and methods to more efficiently track movement of a polishing material in a roll-to-roll polishing system. In some implementations, the present disclosure provides a polishing material having a plurality of identifying feature(s) formed on a backside surface of the polishing material that can be detected by a sensor. In some implementations, the identifying feature(s) allow the position of the polishing material to be determined. In some implementations, the identifying feature(s) are associated with a pattern of polishing features on the polishing surface of the polishing material, thus allowing the user to position the polishing material such that a substrate to be polished is exposed to a desired pattern of polishing features of the polishing material. The identifying feature(s) may extend along the length of the polishing material. The identifying feature(s) may include a first start of line feature, which identifies a start of a first polishing region of polishing material, and a second start of line feature, which identifies an end of the first polishing region and a start of a second polishing region of polishing material. The first polishing region of polishing material and the second polishing region of polishing material may define similar or substantially similar patterns of polishing material, which allows the user to expose subsequently polished substrate to the same pattern of features as previously polished substrates. In some implementations, the identifying feature(s) are used as an authentication mechanism. For example, different types of polishing material may be associated with different polishing recipes and due to the precise nature of polishing features on each type of pad material, it is desirable to identify that the proper type of polishing material is used for the desired polishing recipe. The identifying feature(s) may include, for example, an optical contrast or color marking compared to the unmarked polishing material, laser marking or cutouts in the polishing material, a bar code, or any other suitably identifiable feature.

In some implementations, the apparatus and methods described herein increase the accuracy and placement of the polishing material relative to the substrate, which decreases the cost to produce semiconductor devices and the cost of ownership of a semiconductor device production line.

CMP Hardware Implementation Examples

FIG. 1 depicts a plan view of a polishing module 106 according to one or more implementations disclosed herein. The polishing module 106 may be a portion of a REFLEXION® Chemical Mechanical Polisher, such as the REFLEXION® WEBB™ system, the REFLEXION® LK CMP system, the REFLEXION® LK PRIME™ CMP system, all of which are manufactured by Applied Materials, Inc., located in Santa Clara, Calif. One or more of the implementations described herein may be used on these polishing systems. However, one skilled in the art may advantageously adapt implementations as taught and described herein to be employed on other types of polishing devices produced by other manufacturers that utilize polishing articles, and particularly polishing articles in a roll-to-roll polishing article format. The apparatus description described herein is illustrative and should not be construed or interpreted as limiting the scope of the implementations described herein.

The polishing module 106 generally comprises a loading robot 104, a system controller 108, a transfer station 136, a plurality of processing or polishing stations, such as a platen assembly 132, a base 140 and a carousel 134 that supports a plurality of polishing or carrier heads 152 (only one is shown in FIG. 1). Generally, the loading robot 104 is disposed proximate the polishing module 106 and a factory interface (not shown) to facilitate the transfer of substrate(s) 122 therebetween.

The transfer station 136 generally includes a transfer robot 146, an input buffer station 142, an output buffer station 144 and a load cup assembly 148. The input buffer station 142 receives a substrate 122 from the loading robot 104. The transfer robot 146 moves the substrate 122 from the input buffer station 142 to the load cup assembly 148 where the substrate 122 may be transferred to the carrier head 152.

To facilitate control of the polishing module 106 as described above, the system controller 108 comprises a central processing unit (CPU) 110, support circuits 114 and memory 112. The CPU 110 may be one of any form of computer processor that can be used in an industrial setting for controlling various polishers, drives, robots and sub-processors. The memory 112 is coupled to the CPU 110. The memory 112, or computer-readable medium, may be one or more of readily available memory such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, or any other form of digital storage, local or remote. The support circuits 114 are coupled to the CPU 110 for supporting the processor in a conventional manner. These circuits include cache, power supplies, clock circuits, input/output circuitry, subsystems, and the like.

Generally, the carousel 134 has a plurality of arms 150 that each support one of the carrier heads 152. Two of the arms 150 depicted in FIG. 1 are shown in phantom such that the transfer station and an advanced polishing article 123 disposed on or over one of the platen assemblies 132 may be seen. The carousel 134 is indexable such that the carrier heads 152 may be moved between the platen assemblies 132 and the transfer station 136. In another implementation (not shown herein), the carousel 134 is replaced by a circular track and the carrier heads 152 and movable along the circular track. Typically, a chemical mechanical polishing process is performed at each platen assembly 132 by moving the substrate 122 retained in the carrier head 152 relative to the advanced polishing article 123 supported on the platen assembly 132.

In some implementations, the advanced polishing article 123 may be positioned across the platen assembly 132 and between a supply assembly 156 and a take-up assembly 158 so that a polishing process can be performed on surface of the advanced polishing article 123 on the platen assembly 132. The supply assembly 156 and the take-up assembly 158 may provide an opposing bias to the advanced polishing article 123 in order to tighten and/or stretch an exposed portion of the advanced polishing article 123 disposed therebetween. The supply assembly 156 and the take-up assembly 158 are capable of an intermittent motion actuated in a controlled manner for the necessary time; this motion enables the advanced polishing article 123 to be advanced step-by-step in a controlled manner.

In some implementations, the advanced polishing article 123 may have a flat or planar surface topology when stretched between the supply assembly 156 and the take-up assembly 158. Additionally, the advanced polishing article 123 may be advanced across and/or be releasably fixed to the platen assembly 132 such that a new or unused area of the advanced polishing article 123 may be released from the supply assembly 156. Typically, the advanced polishing article 123 is releasably fixed by a vacuum pressure applied to a backside surface of the advanced polishing article 123, mechanical clamps, or by other holding methods to the platen assembly 132 while a substrate is being polished.

As discussed herein, a polishing article, such as the advanced polishing article 123 may include at least one of a raised surface texture (e.g., embossed texture) formed on a polishing surface and a plurality of grooves extending from the polishing surface toward a backside surface, such as the discrete extended elements and grooves, as, for example, illustrated in FIG. 3. The advanced polishing article 123 further includes a pattern of identifying feature(s), as shown in FIG. 4, formed on a backside surface of the polishing material that may be detected by a sensor. The pattern of identifying feature(s) may be used to identify the position of the advanced polishing article 123 relative to a platen and/or the substrate 122 to be polished. The pattern of identifying feature(s) may also be used as an authentication mechanism. An identifying feature may include a desired physical or optically significant feature or pattern that is formed within, formed on, or formed by removing or altering a portion of a surface of the polishing pad.

The polishing process may utilize a slurry containing abrasive particles delivered to the polishing article's surface by the fluid nozzles 154 to aid in polishing the substrate 122. Alternatively, the fluid nozzles 154 may deliver de-ionized water (DIW) alone, or in combination with polishing chemicals. The fluid nozzles 154 may rotate in the direction shown to a position clear of the platen assemblies 132 as shown, to a position over each of the platen assemblies 132. In one implementation, the fluid nozzles 154 track with the seeping motion of the carrier head 152 so the slurry is deposited adjacent to the carrier head 152.

FIG. 2 depicts a side view of the platen assembly 132 and one implementation of the supply assembly 156 and the take-up assembly 158, illustrating the position of the advanced polishing article 123 across a platen 230. Generally, the supply assembly 156 includes the supply roll 254, an upper guide member 204 and a lower guide member 205 that are disposed between sidewalls 203 of the platen assembly 132. Generally, the take-up assembly 158 includes a take-up roll 252, an upper guide member 214 and a lower guide member 216 that are all disposed between the sidewalls 203. The take-up roll 252 generally contains a used portion of the advanced polishing article 123 and is configured to be easily replaced during a maintenance activity with an empty take-up roll once the take-up roll 252 is filled with used advanced polishing article 123. The upper guide member 214 is positioned to lead the advanced polishing article 123 from the platen 230 to the lower guide member 216. The lower guide member 216 leads the advanced polishing article 123 onto the take-up roll 252. The advanced polishing article 123 generally follows the path “A” shown in FIG. 2.

The platen assembly 132 may also include a detection system 220 that is adapted to transmit and receive output signals for detecting the precise position of the advanced polishing article 123. Although the detection system 220 is positioned internal to the platen assembly 132 it should be understood that in some implementations, the detection system 220 may be positioned external to the platen assembly 132. The detection system 220 may be positioned to detect the pattern of identifying feature(s) positioned on the backside surface of the advanced polishing article 123. The detection system 220 is positioned a known distance from the platen 230. The detection system 220 may be able to detect contrast between different colors, textures, thickness, or cutouts, for example, of the identifying feature(s) compared to the advanced polishing article 123. The location data of the advanced polishing article 123 can be used by the system controller 108 to position the advanced polishing article 123 relative to the platen assembly 132 to improve the repeatability of polishing between substrates. In some implementations, if the identifying feature(s) indicate that the advanced polishing article 123 is misaligned, the advanced polishing article 123 is advanced or “indexed” until the optical sensing device identifies a suitable position to polish a substrate. In some implementations, the advanced polishing article 123 is advanced or “indexed” until the optical sensing device identifies a start of line identifying feature, which indicates that the advanced polishing article 123 is in the proper position to polish a substrate.

In some implementations, the pattern of identifying feature(s) function as an authentication feature. The detection system 220 may be positioned to detect and/or identify the identifying feature(s). Since different types of polishing material may be associated with different polishing recipes and due to the precise nature of polishing features on each type of polishing material, it is desirable to identify that the proper type of polishing material is used for the desired polishing recipe. If the detection system 220 authenticates the identifying feature, then the advanced polishing article 123 is allowed to operate on the platen assembly 132. However, if the detection system does not authenticate the identifying feature, then the advanced polishing article 123 will not operate on the platen assembly 132.

In some implementations, the detection system 220 includes an optical sensing device, such as a laser, that is adapted to transmit and receive optical signals for detecting the identifying feature(s) positioned on the backside surface of the advanced polishing article 123. In some implementations, the detection system 220 includes an optical sensing device that projects radiation through the advanced polishing article 123 and receives at a detector (not shown) any radiation reflected from the surface of the substrate that passes back through the advanced polishing article 123. In some implementations of the present disclosure the polymeric material of the advanced polishing article 123 is optically transparent, so that a “through beam” type (see FIG. 6A) can optically monitor the identifying feature(s) during polishing using the detection system 220.

In a “through beam” type detection configuration, at least a portion of the advanced polishing article 123 may be formed from a material that has an optical clarity that is at least about 25% (e.g., at least about 50%, at least about 80%, at least about 90%, at least about 95%) for light transmission over the wavelength range of the light provided from and collected by the detection system 220. Typical detection wavelength ranges can include the visible spectrum (e.g., from about 400 nm to about 800 nm), the ultraviolet (UV) spectrum (e.g., from about 300 nm to about 400 nm), and/or the infrared spectrum (e.g., from about 800 nm to about 1550 nm), such as wavelength ranges between about 200 nm and about 1600 nm. In one implementation, at least a portion of the advanced polishing article 123 (e.g., identifying feature(s) 520) is formed from a material that has a transmittance of >35% at wavelengths between 280-399 nm, and a transmittance of >70% at wavelengths between 400-800 nm. Conversely, in a “reflective” type of sensing configuration (see FIG. 6B), at least a portion of the advanced polishing article 123 (e.g., identifying feature(s) 520) may be formed from a material that has an ability to reflect at least a portion of the detection wavelength ranges described above, such as between about 200 nm and about 1600 nm. In one example, the portion of the advanced polishing article 123 is configured to reflect >35% at wavelengths between 280-399 nm, and reflect >70% at wavelengths between 400-800 nm.

The supply roll 254 generally contains an unused portion of the advanced polishing article 123 and is configured so that it may easily be replaced with another supply roll 254 containing a new advanced polishing article 123 once the advanced polishing article 123 disposed on the supply roll 254 has been consumed by the polishing or planarizing process. In general, the total length of the advanced polishing article 123 includes an amount of polishing material disposed on the supply roll 254, an amount disposed on the take-up roll 252, and an amount that extends between the supply roll 254 and the take-up roll 252. The total length is typically larger than the size of the polished surface of multiple substrates 122 (FIG. 1), and may be for example several meters to several tens of meters long.

The advanced polishing article 123 is generally configured to controllably advance the advanced polishing article 123 in the X-direction across a backing pad assembly 226. The advanced polishing article 123 is generally moved in relation to the platen 230 by balancing the forces between a motor 222 coupled to the supply assembly 156 and a motor 224 coupled to the take-up assembly 158. Ratchet mechanisms and/or braking systems (not shown) may be coupled to one or both of the supply assembly 156 and the take-up assembly 158 to fix the advanced polishing article 123 relative to the backing pad assembly 226. The platen 230 may be operably coupled to a rotary actuator 228 that rotates the platen assembly 132 and the advanced polishing article 123 about a rotational axis 235 generally orthogonal to the X and/or Y directions. In some implementations, all of the elements shown in FIG. 2 rotate about the rotational axis 235.

A vacuum system 232 may be coupled between the rotary actuator 228 and the backing pad assembly 226. The vacuum system 232 may be used to fix the position of the advanced polishing article 123 onto the platen 230. The vacuum system 232 may include channels 234 formed in a plate 236 disposed below the backing pad assembly 226. In one implementation, the backing pad assembly 226 may include a subpad 240 and a subplate 238, each having openings 242 formed therethrough that are in fluid communication with the channels 234 and a vacuum source (not shown). In other implementations, an integral subpad 250 (shown in dashed lines) may be formed on a lower surface of the advanced polishing article 123. In one implementation of the platen assembly 132, a subpad 240 and an integral subpad 250 of the advanced polishing article 123 are used in combination during a polishing process. In some implementations, the subpad 240 and/or the integral subpad 250 is typically formed from a polymeric, elastomeric, woven fiber or plastic material, such as polypropylene, polycarbonate or polyurethane. In one implementation, the subpad 240 and/or the integral subpad 250 is formed from woven fiber polypropylene. In some implementations, portions of plate 236 and the backing pad assembly 226 have optical clarity sufficient to accommodate the detection beam of the detection system 220.

Generally, the hardness, thickness and durometer of the subpad 240 and/or the integral subpad 250 may be chosen to produce a particular polishing result. The subpad 240 and/or the integral subpad 250 generally maintains an upper surface 221 of the advanced polishing article 123 in a plane that is parallel to the plane of a substrate (not shown) in order to promote global planarization of the substrate. In some implementations, the subplate 238 may be positioned below the subpad 240, as shown. The subpad 240 and/or the integral subpad 250 may be hydrophilic or hydrophobic. If the subpad 240 and/or the integral subpad 250 is hydrophilic, the subpad 240 and/or the integral subpad 250 should be configured to absorb in a uniform manner.

The advanced polishing article 123 as described herein may alleviate the need to condition the polishing article and thus maximize polisher availability and polisher performance. For example, the advanced polishing article 123 may be incrementally advanced a distance smaller than the size (e.g., diameter) of the substrate to present a portion of fresh polishing material in lieu of the need to perform abrasive conditioning. The incremental advancement of the advanced polishing article 123 may be performed before, during or after a substrate is polished thereon by use of one or more actuators coupled to the take-up roll 252 or supply roll 254 (FIG. 2). In one implementation, the advanced polishing article 123 is incrementally advanced from about 0.1 millimeters per wafer to about 10 millimeters per wafer (e.g., 1 millimeter per wafer to about 5 millimeters per wafer).

FIG. 3 is an enlarged schematic side view of one implementation of the advanced polishing article 123, according to one or more implementations of the present disclosure. The advanced polishing article 123 includes a top pad 310 having a polishing surface 312 and an opposing backside surface 314 that define a pad body 330. The backside surface 314 has identifying feature(s) 520A, 520B (collectively 520) formed thereon as described herein. In one implementation, as depicted in FIG. 3, the polishing surface 312 is textured and includes a plurality of micro-features or discrete extended elements 340 extending from the polishing surface 312 of the advanced polishing article 123. In one implementation, the texture is formed by embossing or other methods of forming a raised surface texture on the polishing surface 312 the top pad 310. In one implementation, the discrete extended elements 340 of the polishing surface 312 have an average height “h” from about 1 micron to about 50 microns (e.g., from about 5 microns to about 30 microns, from about 10 microns to about 20 microns; or from about 5 to 10 microns). In one implementation, the texture formed by the raised surface texture is spatially uniform or substantially spatially uniform in a plane that is parallel to the polishing surface of the top pad 310.

The top pad 310 is typically formed from synthetic materials. Non-limiting examples of suitable synthetic materials include films, such as polymeric or thermoplastic films, webs comprising sustainable polymers, and the like. Suitable precursor webs further include laminates or blends of these materials. In one implementation, the top pad 310 is a polymeric sheet or film. In some implementations, the top pad 310 includes a non-porous polymeric material. Suitable polymeric films include thermoplastic films composed of polymeric materials such as polyethylene (PE), polypropylene (PP), polystyrene, polyethylene terephthalate (PET), poly(methyl methacrylate) (PMMA), polyvinyl alcohol (PVA), polytetrafluoroethylene (PTFE) (e.g., TEFLON), polyamides (e.g., nylon), polyurethane, or combinations thereof. Suitable polymeric films can include blends or mixtures of polymers. In one implementation, the top pad 310 is a polypropylene-based sheet.

The advanced polishing article 123 as described herein includes a thickness that is generally less than a conventional CMP polishing pad, which allows a longer length of the polishing article material to be disposed on the same sized supply roll. The polishing article's thickness is generally measured in a direction that is parallel to the direction that the force is applied to the advanced polishing article 123 by the substrate when it is being polished. In some implementations, the advanced polishing article 123 has a thickness in a range from about 0.001 inches to about 0.025 inches.

In some implementations, the plurality of discrete extended elements 340 are formed as protruded extensions of the top pad 310, generally on the polishing surface 312 thereof. The number, size, and distribution of the discrete extended elements 340 on the polishing surface 312 can be predetermined based on the desired polishing characteristics of the top pad 310. For most polishing applications, it can be desired that the plurality of the discrete extended elements 340 protrude only from one surface (e.g., the top surface) of the top pad 310. In some implementations, the top pad 310 does not contain macro-features (e.g., grooves, channels or other identifiable surface structure), but includes a random, semi-random, or uniform (e.g., long range repeating) texture of micro-features (e.g., discrete extended elements 340) having varying heights and lateral spacing.

Referring to FIG. 3, in some implementations, the discrete extended elements 340 can be described as protruding from the polishing surface 312 of the pad body 330. As such, the discrete extended elements 340 can be described as being integral with the pad body 330, and formed by permanent local plastic deformation of the pad body 330.

In some implementations, the top pad 310 further includes a plurality of macro-features or groove(s) 342 formed in the polishing surface 312. The groove(s) 342 formed in the top pad 310 can function as local reservoirs for the polishing slurry during a polishing process. The groove(s) 342 may be formed in the top pad 310 using any suitable groove forming methods (e.g., laser cutting, water jet cutting, die cutting, stamping, punch press, etc.). A bottom portion 350 of the top pad 310 is contiguous and prevents liquids such as polishing slurry or water from penetrating the top pad 310. In this configuration, the groove(s) 342 formed through the top pad 310 become local reservoirs for the polishing slurry, since the slurry is retained in the formed grooves and the polishing slurry will generally not penetrate the bottom portion 350 of the top pad 310. For multiple reasons including holding down the pad during polishing and polisher cleanliness, it is undesirable for the slurry to penetrate the top pad 310 through the groove(s) 342 in the top pad 310.

In one implementation, the groove(s) 342 has a width between about 0.05 inches and about 0.50 inches (e.g., between about 0.10 inches to about 0.40 inches, between about 0.15 inches to about 0.20 inches, or between about 0.18 inches to about 0.20 inches). In one implementation, the spacing between adjacent grooves 342 is between about 0.5 inches and about 2.5 inches (e.g., between about 1 inch to about 2 inches, between about 1 inch to about 2 inches, or between about 1 inch to about 1.5 inches).

In some implementations, at least one identifying feature of the pattern of identifying features is positioned a fixed distance from at least one polishing feature. Positioning the at least one identifying feature a fixed distance from the at least one polishing feature makes it so the at least one identifying feature can be used to identify the position of the polishing feature. For example, as depicted in FIG. 3, identifying feature 520B is positioned a fixed distance 701 from groove 342. Positioning identifying feature 520B the fixed distance 701 from groove 342 allows for the position of groove 342 to be identified by identifying feature 520B. In addition, since the detection system 220 is positioned a known distance from the platen 230, the position of the platen 230 relative to the position of the polishing features may be determined using the identifying feature(s).

FIG. 4 is a schematic top view of a portion of a roll-to-roll type of an advanced polishing article 400 having a polishing surface 412 with grooves 432 formed therein, according to one or more implementations of the present disclosure. In one implementation, the advanced polishing article 400 may form part of or be used in place of the advanced polishing article 123. The polishing surface 412 may be textured as described herein. The texture of the polishing surface 412 may be similar to the texture of the polishing surface 312. The grooves 432 formed may be similar to groove(s) 342 of advanced polishing article 123. The pattern of grooves 432 of the advanced polishing article 123 includes a sawtooth pattern of grooves 432 that are aligned relative to the index axis 440 and or the axis of movement 450 along path “A.”

FIG. 5 is a close up isometric view of a portion of a backside surface 514 of an advanced polishing article 500 having a pattern of identifying feature(s) 520 formed thereon according to one or more implementations of the present disclosure. The pattern of identifying feature(s) 520 may include, for example, an optical contrast or color marking compared to the unmarked polishing material, laser marking or cutouts in the polishing material, a bar code, or any other suitably identifiable feature. In one implementation, the advanced polishing article 500 may form part of or be used in place of the advanced polishing article 123. The backside surface 514 of the advanced polishing article 500 is positioned adjacent to the detection system 220. The detection system 220 is used to monitor and feedback the polishing material of the advanced polishing article 500 movement and position data to the system controller 108.

In general, the movement and position of the advanced polishing article 500 can be monitored by use of a sensor assembly 260 in the detection system 220 that is positioned to view one or more regions of the backside surface 514 of the advanced polishing article 500 that has identifying feature(s) 520 formed thereon. The sensor assembly 260 is typically a non-contact sensor. The identifying feature(s) 520 of formed elements may include a regular pattern of deposited material or formed features that can be detected by the sensor assembly 260, so that a processor (e.g., CPU 110) in the system controller 108 can then analyze the detected signal, as it passes through a detection region 530 of the sensor assembly 260. In one implementation, the identifying feature(s) 520 are a regular array of printed ink lines that are deposited on the backside surface 514 of the advanced polishing article 500. In another implementation, the identifying feature(s) 520 is an array of embossed features in the backside surface 514 of the advanced polishing article 500. In yet another implementation, the identifying feature(s) 520 is an array of regions of removed polishing material, such as holes. The term holes as used herein may include but is not limited to round holes, oval holes, polygon shaped holes, slots, grooves, cuts or other similar feature that are formed in the polishing material.

In one implementation, as depicted in FIG. 5, the identifying feature(s) 520 comprises an array of equally spaced features (e.g., lines) that are disposed on or formed in the backside surface 514 of the advanced polishing article 500 that passes through and are sensed by the components in the sensor assembly 260.

The sensor assembly 260 generally contains one or more components that are able monitor the movement of the identifying feature(s) 520 as it is moved by the components in the supply assembly 156 and the take-up assembly 158, and regularly or continually deliver a detection signal to the system controller 108 based on the monitored movement. The sensor assembly 260 may utilize optical monitoring techniques, capacitive measurement technique, eddy current measurement techniques, or other similar suitable technique that is able to detect the motion of the identifying feature(s) 520 as it passes by the sensor assembly 260. As noted above, the sensor assembly 260 will include a light source 610 and a detector 620 that are in communication with the system controller 108. Typically, the light source 610 generally contains a source of some form of electromagnetic energy, such as light delivered from an LED or a laser that is emitted and directed at the backside surface 514 of the advanced polishing article 500. Typically, the detector 620 is conventional optical detector, such as a photoconductive sensor, thermoelectric detector, AC type optical sensor, DC type optical sensor, or other similar device that is adapted to detect the variation in intensity of the energy delivered by the light source 610 due to the interaction of the energy with the identifying feature(s) 520.

In one implementation, each platen assembly 132 contains two or more sensor assemblies 260 that are each positioned to detect the motion of the identifying feature(s) 520, and are used in combination with the system controller 108 to determine the actual motion of the advanced polishing article 500. In one implementation, the two or more sensor assemblies 260 are positioned to monitor different portions of the identifying feature(s) 520 so that the actual position can be determined.

In one implementation, the shape or one or more materials in the formed identifying feature(s) 520 preferentially absorbs or reflects one or more wavelengths of light delivered from the light source 610 that is sensed by the detector 620. In one implementation, an array of equally spaced lines of an ink material are deposited on the backside surface 514 of the advanced polishing article 500 which is seen as a series of signal intensity peaks and valleys by the detector 620 and the system controller 108 as the identifying feature(s) 520 is moved past the sensor assembly 260. The system controller 108 may use the intensity peaks and valley information to determine how much the advanced polishing article 500 has been moved past the sensor assembly 260 or determine the actual position of a portion of the advanced polishing article 500 (e.g., position of the identifying feature(s) relative to the position of polishing feature(s) on the pad material; position of identifying features relative to the substrate to be polished; position of the identifying feature(s) relative to the platen; or position of the polishing features relative to the platen). In some implementations, the shape of the features within the identifying feature(s) 520 (e.g., length of bar shaped features in one direction) may change from one region of the roll of the advanced polishing article 500 to another (i.e., start of a roll of polishing material to the end of the roll of polishing region), thus providing some information about the actual position of a region of the advanced polishing article 500 on the roll. In some implementations, the shape of the features within the identifying feature(s) 520 may change from one polishing region of the roll of the advanced polishing article 500 to another polishing region (i.e., start of the repeating pattern of the polishing surface to the end of the repeating pattern), thus indicating where a new region of polishing material begins such that subsequent substrates are exposed to new polishing material with the same polishing pattern as previously polished substrates.

One skilled in the art will appreciate that any known shaped or spaced identifying feature(s) 520 could be used to provide information to the system controller 108 about the movement of the advanced polishing article 500 without deviating from the basic scope of the disclosure described herein. In one example, the identifying feature(s) 520 includes a distinct analog or digitally encoded pattern that the detector and system controller are able to analyze using a pattern recognition and/or signal processing technique.

FIG. 6A is a schematic sectional view of the processing station of FIG. 2 having one implementation of the sensor assembly 260 positioned therein, according to one or more implementations disclosed herein. The sensor assembly 260 depicted in FIG. 6A uses a through-beam sensor configuration to monitor the movement of the advanced polishing article 500. In this implementation, the sensor assembly 260 generally includes a light source 610 that is positioned to provide electromagnetic radiation (e.g., light) to a detector 620 that is disposed on the opposite side of the advanced polishing article 500. Therefore, the detector 620 receives the interference or interaction of the energy delivered by the light source 610 with the identifying feature 520 so that the movement and/or position of the material can be controlled. In one implementation, the electromagnetic energy delivered by the light source 610 is passed through an array of holes or thinned regions formed in the in the advanced polishing article 500, and thus the presence or absence of the advanced polishing article 500 in the identifying feature(s) 520 is used to monitor the movement and/or position of the advanced polishing article 500. In another implementation, the electromagnetic energy delivered by the light source 610 primarily passes through the advanced polishing article 500, and thus the presence of a material in the identifying feature(s) 520 (e.g., ink) is used to alter the energy received by the detector 620 to help provide information about the movement of the advanced supporting article. In one implementation, the light source 610 delivers light through a hole 630 formed in the plate 236 and hole 640 formed in the subpad 240. In some implementations, at least one of the hole 630 and the hole 640 have a window positioned therein.

FIG. 6B is a schematic sectional view of the processing station of FIG. 2 having another implementation of the sensor assembly 260 positioned therein, according to one or more implementations disclosed herein. The sensor assembly 260 uses reflected energy to monitor the movement of the advanced polishing article 500. In this implementation, the sensor assembly 260 generally includes a light source 610 that illuminates “B1” the detection region 530 (FIG. 5) on the advanced polishing article 500 containing the identifying feature(s) 520 and receives an amount of reflected light “B2” at the detector 620 that is altered by the interference or interaction with the identifying feature(s) 520. The altered energy received by the detector 620 due to the interaction with the identifying feature(s) 520 is fed back to the system controller 108 so that the movement and/or position of the advanced polishing article 500 can be controlled. In one implementation, the electromagnetic energy delivered by the light source 610 is designed to preferentially reflect from the backside surface 514 of the advanced polishing article 500 or the material from which that the identifying feature(s) 520 is formed, so that the movement of the identifying feature(s) 520 can be monitored by the system controller 108.

Polishing Process Examples

FIG. 7 is a flow chart depicting one example of a method 700 of polishing with an advanced polishing article having identifying feature(s) according to one or more implementations described herein. The advanced polishing article may be, for example, any of the advanced polishing articles described herein (e.g., advanced polishing article 123, advanced polishing article 400, or advanced polishing article 500). The method may be performed, for example, with any of the polishing modules depicted herein using any of the aforementioned advanced polishing articles.

At operation 710, the advanced polishing article is advanced using the supply roll 254 and the take-up roll 252. In some implementations, the advanced polishing article is advanced relative to the platen before and/or during removing material from the substrate 122 by use of an actuator coupled to the supply roll and/or an actuator coupled to the take-up roll. In one implementation, the advancing comprises advancing the polymeric sheet between about 1 mm and about 5 mm relative to the platen. In one implementation, the advanced polishing article is a polymeric sheet. As discussed herein, the advanced polishing article has a textured polishing surface (e.g., polishing surface 312 or 412 is textured) including, at least one of a microtexture (e.g., plurality of discrete elements) formed from the pad material and extending upward from the polishing surface and a plurality of macro-features (e.g., grooves) formed in the polishing surface. The speed with which the advanced polishing article is advanced may be based on a process recipe, for example, or other processing parameters such as an optimized polishing speed.

At operation 720, the detection system 220 may detect and/or sense the movement of an identifying feature (e.g., identifying feature(s) 520) on the backside surface of the advanced polishing article. The one or more detector assemblies may be selected from, for example, a capacitive type sensor, an optical measurement sensor, or an eddy current measurement sensor. In some implementations, the identifying feature is associated with (e.g., positioned a known distance from) a specific polishing feature on the polishing surface of the polishing article. For example, as depicted in FIG. 3, identifying feature 520B is positioned a fixed distance 701 from groove 342. Positioning identifying feature 520B the fixed distance 701 from groove 342 allows for the position of groove 342 to be identified by identifying feature 520B. In addition, since the detection system 220 is positioned a known distance from the platen 230, the position of the platen 230 relative to the position of the polishing features may be determined using the identifying feature(s).

The polishing features may include, for example, at least one of grooves formed in the polishing surface and a plurality of discrete features that extend upward from the polishing surface. In some implementations, the identifying feature is associated with a fixed groove pattern that has a fixed pitch. Associating the identifying feature with a specific polishing feature or characteristic of a polishing feature allows the precise positioning of the polishing material, and more particularly the precise positioning of the polishing features formed in the polishing material relative to the substrate to be polished to be determined. In addition, associating the polishing feature with a specific identifying feature allows for determining the position of the polishing feature relative to hardware (e.g., position of the identifying feature(s) relative to the platen; or position of the polishing features relative to the platen.) The detection system 220 may send a signal to the system controller 108 regarding the identifying feature. For example, the detection system 220 emits electromagnetic radiation onto the backside surface of the advanced polishing article, wherein the emitted radiation interacts with the identifying features of the pattern of identifying features formed on the backside surface. The detection system 220 then receives an intensity of the electromagnetic radiation after at least a portion of the electromagnetic radiation has interacted with the identifying features.

At operation 730, the system controller associates the identifying feature(s) with a specific location on the polishing pad. For example, the system controller monitors the intensity of the received electromagnetic radiation to determine the position of the polishing material relative to the platen. In some implementations, the identifying feature(s) is a start of line feature. The start of line feature identifies a start of a polishing region of polishing material where the substrate is polished. In some implementations, the start of line feature(s) includes a first start of line feature, which identifies a start of a first polishing region of polishing material, and a second start of line feature, which identifies an end of the first polishing region and a start of a second polishing region of polishing material. In some implementations, the first polishing region of polishing material and the second polishing region of polishing material have similar or substantially similar patterns of polishing features. For example, with reference to FIG. 3, if the system controller identifies feature 520A as a start of line feature, advancement of the polishing article may be ended at operation 740. If the identifying feature(s) is not a start of line feature, the system controller 108 using the identifying feature(s) to determine the current position of the polishing article. The system controller 108 can determine the distance between the identifying feature(s) and the next start of line feature and advance the polishing article until the next start of line feature is reached. In addition, since the detection system 220 is positioned a known distance from the platen 230, the position of the platen 230 relative to the start of line feature may be determined using the identifying feature(s).

At operation 740, in some implementations, advancement of the polishing article is ended. For example, the polishing material traveling across the surface of the platen is halted when the detector assembly senses identifying features that indicate the start of a first region of polishing material having a desired pattern of polishing features. In some implementations, the advanced polishing article continues to move during the polishing process.

At operation 750, a substrate is urged toward the advanced polishing article. In one implementation, the substrate is substrate 122, which is disposed in a carrier head (e.g., carrier head 152). In some implementations, the advanced polishing article is disposed on a platen (e.g., platen 230 of platen assembly 132).

The substrate 122 may be a silicon-based material or any suitable insulating materials or conductive materials as needed. In one implementation, the substrate 122 may be a material such as crystalline silicon (e.g., Si<100> or Si<111>), silicon oxide, strained silicon, silicon germanium, doped or undoped polysilicon, doped or undoped silicon wafers and patterned or non-patterned wafers silicon on insulator (SOI), carbon doped silicon oxides, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire. The substrate 122 may have various dimensions, such as 200 mm, 300 mm, and 450 mm or other diameter wafers, as well as, rectangular or square panels. Unless otherwise noted, implementations and examples described herein are conducted on substrates with a 200 mm diameter, a 300 mm diameter, a 450 mm diameter substrate.

A polishing slurry is delivered to the polishing surface of the advanced polishing article. Any suitable polishing slurry compatible with the materials polished may be used. In one implementation, the polishing slurry includes at least one of oxidizers, passivation agents, pH buffers, metal complexing agents, surfactants and abrasives. In one implementation, the polishing slurry is delivered to the textured polishing surface via a fluid nozzle (e.g., fluid nozzle(s) 154). In some implementations, the substrate 122 contacts the textured polishing surface after delivery of the polishing slurry. In some implementations, the substrate 122 contacts the textured polishing surface prior to delivery of the polishing slurry. In some implementations, the substrate 122 contacts the textured polishing surface during delivery of the polishing slurry.

The substrate 122 may be urged against the textured polishing surface with a force of less than about 10 pounds per square inch (psi) (e.g., less than about 9 psi; less than about 7 psi; less than about 5 psi; or less than about 2.5 psi). In one implementation, the force is between about 1 psi and 2 psi, for example, about 1.8 psi.

At operation 760, relative motion is provided between the substrate 122 and the polishing surface. In one implementation, the carrier head is rotated at between about 50-100 revolutions per minute, for example, between about 30-60 revolutions per minute, while the platen positioned below the polishing surface is rotated at between about 50-100 revolutions per minute, for example, between about 7-35 revolutions per minute. In some implementation, the advanced polishing article remains stationary while the carrier head and platen rotate. In some implementations, the carrier head, the platen, the supply roll and the take-up roll are rotated relative to the substrate 122.

During operation 760, material is removed from the surface of the substrate 122 by applying a pressure to a surface of the substrate 122, such that the substrate 122 is urged against the polishing surface. The material may be a conductive material (e.g., copper), a dielectric material (e.g., oxide or nitride containing), or both a conductive material and dielectric material. The advanced polishing articles described herein have demonstrated little impact on polishing performance when slurry flow rates are below 100 ml/min, versus conventional polyurethane polishing articles that typically have slurry flow rate that range from 100-300 ml/min with 150 ml/min being very common value.

At operation 770, after polishing is completed, the method 700 returns to operation 710 where additional substrates may be polished. In some implementations, the advanced polishing article is advanced relative to the platen before, during and/or after removing material from the substrate 122 by use of an actuator coupled to the supply roll and/or an actuator coupled to the take-up roll. The polishing article can be advanced until a desired identifying feature(s) is identified. For example, the desired identifying feature (s) may be the next start of line feature, which identifies a fresh region of polishing material. In one implementation, the advancing comprises advancing the polymeric sheet between about 1 mm and about 5 mm relative to the platen.

FIG. 8 is a flow chart depicting another example of a method 800 of polishing with an advanced polishing article having identifying feature(s) used for authentication according to one or more implementations described herein. The advanced polishing article may be, for example, any of the advanced polishing articles described herein (e.g., advanced polishing article 123, advanced polishing article 400, or advanced polishing article 500). The method may be performed, for example, with any of the polishing modules depicted herein using any of the aforementioned advanced polishing articles.

In some implementations, the plurality of identifying feature(s) function as a coded authentication feature. The coded authentication mechanism is capable of being identified by a system controller (e.g., system controller 108). Since different types of polishing material may be associated with different polishing recipes and due to the precise nature of polishing features on each type of pad material, this authentication mechanism allows for verification that the proper type of polishing material is used on the proper platen assembly for the desired polishing recipe. In some implementations, the coded authentication mechanism allows the settings of the platen assembly to be pre-set for a desired polishing recipe.

At operation 810, the advanced polishing article is installed on a platen assembly.

At operation 820, the identifying feature is detected on the backside surface of the advanced polishing article. The detection system 220 may detect the identifying feature on the backside surface of the advanced polishing article. The detection system 220 may be positioned to authenticate the identifying feature.

At operation 830, a system controller (e.g., system controller 108) is used to verify whether the identifying feature is valid. If the system controller authenticates the identifying feature, then the advanced polishing article 123 is allowed to operate on the platen assembly 132. However, if the detection system does not authenticate the identifying feature, then the advanced polishing article 123 is not allowed to operate on the platen assembly 132. For example, in implementations, where the identifying feature(s) identifies the polishing article as a polishing article designed for polishing dielectric materials, polishing recipes and polishing fluids used for polishing metals may be locked out.

At operation 840, if the advanced polishing article is authenticated, a substrate may be polished using the advanced polishing article using, for example, the method 700.

In summary, some benefits of some of the implementations described herein provide apparatus and methods that increase the accuracy and placement of polishing material relative to a substrate, which decreases the cost to produce semiconductor devices and the cost of ownership of a semiconductor device production line. In some implementations, the advanced polishing pads described herein include identifying feature(s) that are associated with a pattern of polishing features on the polishing surface of the polishing material, thus allowing the user to position the polishing material such that a substrate to be polished is exposed to a desired pattern of polishing features of the polishing material. In some implementations, the identifying feature(s) may include a first start of line feature, which identifies a start of a first polishing region of polishing material, and a second start of line feature, which identifies an end of the first polishing region and a start of a second polishing region of polishing material. The first polishing region of polishing material and the second polishing region of polishing material may define similar or substantially similar patterns of polishing material, which allows the user to expose subsequently polished substrate to the same pattern of features as previously polished substrates.

When introducing elements of the present disclosure or examples of aspects or implementation(s) thereof, the articles “a,” “an,” “the” and “said” are intended to mean that there are one or more of the elements.

The terms “comprising,” “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

While the foregoing is directed to implementations of the present disclosure, other and further implementations of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.