The depth distribution of S near to a Si/GaAs(110) interface was measured by using particle-induced X-ray emission techniques, together with Rutherford back-scattering spectrometry. Ozone oxidation and HF etching were used to remove layers. The measurements revealed the presence of a half-monolayer of S on H2Sx-passivated GaAs (110) surfaces. Upon depositing 1.5nm of Si onto S-passivated GaAs (110), the total amount of S was found to remain constant as compared to that before Si deposition. However, no oriented S-Ga bonds were revealed by X-ray absorption measurements, and the depth profiles revealed that S atoms diffused into both the GaAs substrate and the Si hetero-layer.

H.Xia, W.N.Lennard, L.J.Huang, W.M.Lau, J.M.Baribeau, D.Landheer: Journal of Applied Physics, 1996, 80[8], 4354-7