Fabrication of microstructures for integrated sensors on GaAs

This paper demonstrates the different possibilities of micromachining GaAs-based materials for integrated sensors with on-chip integrated circuitry. Special emphasis was laid on the high-temperature applications. The authors report for the first time the microstructuring of GaAs by ion implantation. A GaAs cantilever and Si 3 N 4 diaphragms up to 400 mu m diameter were fabricated using this technology. Using AlGaAs etch-stop layers thin GaAs/AlGaAs membranes can be produced easily. This technique results in excellent thermal isolation. An anemometer with an integrated electronic circuit is presented.