New technique makes it easier to etch semiconductors

Researchers have developed a new method to chemically etch patterned arrays in the semiconductor gallium arsenide (GaAs), which is used in solar cells, LEDs, capacitors and sensors. Semiconductors are commonly etched with two techniques: Wet etching uses a chemical solution to erode the semiconductor in all directions, while dry etching uses a directed beam of ions to bombard the surface, carving out a specific pattern. Such patterns are essential to many high-end optoelectronic devices. Unfortunately, dry etching can be difficult, as the high-energy ion blasts can damage the semiconductor's surface. To address this problem, researchers turned to metal-assisted chemical etching (MacEtch), a wet etching approach previously developed for silicon, which is faster and less expensive than many dry etch techniques. The researchers successfully used the MacEtch technique, optimizing the chemical solution and reaction conditions for GaAs.