Laser-induced direct etching of GaAs using chlorofluorocarbon (CFC) alternative gases

Abstract

Non-ozone layer destructive chlorofluorocarbon (CFC) alternatives have been initially used for laser-induced thermochemical etching of GaAs. The CFC alternatives used here are CHClF2 and C2H2F4. Respective etching rates of 188 and 160 mu m/s were achieved using CHClF2 and C2H2F4 gases. Aspect ratios of 2.5 and 1.5 were achieved with a single laser scan for CHClF2 and C2H2F4, respectively. The presence of some reaction products deposited on the etched region was dependent on three variables: laser power, scan speed, and gas pressure. Chemical compositions of the reaction products were measured by Auger electron spectroscopy.