Mechanical stress caused by adsorption of O or N on a Ga-terminated (100) GaAs surface: O gives compressive stress but N don´t

Effects of adsorption of O or N on a (1 × 1)-(100) Ga-terminated GaAs were studied using small cluster models and first principle calculations. Calculation results suggest that oxidation gives compressive stress to the surface but nitridation don´t. This partly explains that nitridation improves crystal disorder of oxidized GaAs. The authors calculated similar adsorption effects on InAlAs. Nitridation-after-oxidation does not realize a good interface on an InAlAs surface.