Abstract

The chemically assisted ion beam etching (CAIBE) of GaAs as well as the sputtering and the pure chemical etching (CE) at different surface temperatures and chlorine fluxes have been studied. At elevated surface temperature a noticeable increase of the etch rate compared to room temperature etching for CE and CAIBE was achieved whereas sputtering is not depending on the temperature. An etch rate of higher than 1 µm/min at an ion beam energy of 400 eV, a chlorine flux of 10 sccm Cl2, and a temperature of 420 K could be obtained. An electronic beam chopper has been utilised in order to obtain a better insight into the kinetics of the formation and the etching process of the reaction products. A lower pulse length modulation reduces the total ion beam exposure time at the same etch depth. Hence, a lower surface damaging could be the consequence.