In-situ IR observation of etching and oxidation processes of Si surfaces

We have used infra-red absorption spectroscopy (IRAS) in the multiple inter nal reflection (MIR) geometry to investigate in-situ and real-time etching and oxidation processes on Si surfaces. IRAS-MIR, with its high surface sen sitivity and energy resolution, is particularly suitable for investigating the atomic bonding configuration of hydrogen in the Vicinity of the surface . We present the experimental results on (1) etching of Si(100) by atomic h ydrogen, (2) oxidation of Si(100) by the water molecule, (3) hydrogen excha nge reaction on Si surface in water and (4) oxidation of Si surface in wate r. IR data show that hydrogen plays an important role in the etching and ox idation processes on Si surfaces, and that MIR-IR is a powerful tool for th e atomic-scale investigation of chemical processes on Si surfaces. (C) 1999 Elsevier Science B.V. All rights reserved.