NOVEL INSITU PATTERN ETCHING OF GAAS BY ELECTRON-BEAM-STIMULATED OXIDATION AND SUBSEQUENT CL2 GAS ETCHING

A new method for in situ pattern etching of GaAs was demonstrated by using an electron-beam (EB)-stimulated-oxidized surface layer as a mask for subsequent Cl2 gas etching. This process is based on the experimental results that GaAs oxide prepared by EB irradiation under an oxygen atmosphere is resistive to Cl2 gas etching, whereas GaAs oxide without an EB can be easily etched. The resistance of the oxide mask against Cl2 gas etching varies depending on the EB dose with which the oxide of GaAs is formed. A fine pattern, such as a 1-mu-m linewidth in a 5-mu-m pitch line-and-space, is obtained.