Dry etching process using XeF2 on microhotplate device

This paper discusses about the etching process using isotropic dry etching (XeF₂) in order to get a suspended structure in microhotplate device. Suspended structure is important for thermal dissipation. In the etching process, the pressure of nitrogen gas is fixed to 0 Torr and the pressure of XeF₂ is fixed to 2.5Torr. Before the etching process, the samples are cleaned with HF (0.5M) for 10 second, 30 second and 60 second. The etching process has been carried out with six differences etching time; 10 cycles (5 seconds per cycle), 10 cycles (10 seconds per cycle), 10 cycles (12 seconds per cycle), 10 cycles (15 seconds per cycle), 10 cycles (20 seconds per cycle) and 10 cycles (22 seconds per cycle). Results show that the optimum period for HF cleaning process is 30s. Results also show that the etch rate is 0.5378μm/s and the etching period to become a suspended structure is 200second or 10 cycles (20 second per cycle).