Vapor HF Etch
applications of this tool are mainly in MEMS-device fabrication areas (releasing a MEMS structure by etching a sacrificial SiO2 layer below) with the use of Al2O3, Al or some other metal as an etch mask at 45oC. The tool uses vapor HF (VHF), EtOH (Ethanol vapor is an Alcohol-based one, ionizing the HF and activating etching, influencing within wafer etch uniformity, and being most compatible with VHF), and N2 gases and can process small sample(s) (on a 8" Si carrier wafer) up to an 8" wafer. There are 5 standard etch recipes installed in the tool with the SiO2 etch rate from low to high. The SiO2 under etch rate is from ~10nm/min to ~350nm/min.