Micromachining and nanoprocessing of GaN/Silicon for SAW and UV photodetector manufacturing

The paper presents the manufacturing and the characterization of two novel devices on GaN/Si. The first device is a SAW structure for the GHz frequency range manufactured using nanolithografic techniques on GaN. Fingers and intedigits spacing 300nm wide have been successful developed in a single metal PMMA layer. An operating frequency close to 4 GHz has been obtained. For the second device, a membrane supported MSM UV photodetector on GaN, both micromachining techniques and nanolithography have been used. The MSM interdigitated structure of the photodetector had 500nm wide fingers/spacings. A very high responsivity (about 10 A/W for 6V) and the very low dark current (<;1pA for V=3V) have been obtained.