Hydrogen plasmas were used to etch surfaces of semiconducting materials (e. g. , GaAs, GaSb, InP, Si), their oxides, and Si nitride. Using a combination of analytical techniques - spectroscopic ellipsometry, Auger spectroscopy, and scanning electron microscopy (SEM), the etch rates, the surface composition and morphology have been studied. It is demonstrated that the selective etching rate of hydrogen plasma for Si over SiO//2 is approximately 30, and that for GaAs oxide over GaAs is approximately 2. It is also shown that the hydrogen plasma etched (and air exposed) GaAs surfaces have a Ga/As concentration ratio nearly equal to that of the air cleaved GaAs surface. Similar results have also been obtained for GaSb. Hydrogen plasma etched InP shows surface segregation and is rich in In.
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