IN-SITU PATTERN ETCHING OF GAAS BY TRIMETHYLINDIUM AND H2O2 GASES WITH ELECTRON-BEAM-INDUCED RESIST

Abstract

We have studied in situ pattern etching of GaAs by trimethylindium (TMIn) and H2O2 gases with an electron-beam-induced carbon resist. The carbon resist pattern for selective etching was prepared on the GaAs surface by electron beam scanning in TMIn ambient at room temperature, and then the selective etching of GaAs was carried out in situ with TMIn and H2O2 gases at temperatures above 600-degrees-C. The etching depth at 650-degrees-C by this gas system was about four times higher than that by H2O2 gas only. This etching process appeared also using the triethylindium (TEIn) and H2O2 system. This points to the possibility of using the metalorganic and H2O2 gas system as an etchant gas; the carbon resist pattern has an advantage as a mask for in situ selective etching to fabricate nanoscale heterostructures.