X-Ray Reflectometry and Infrared Analysis of Native Oxides on Si (100) Formed by Chemical Treatment

Abstract
We investigated native-oxide formation on Si(100) in some cleaning solutions. The macroscopic density and thickness of the native oxides were determined by glancing incidence X-ray reflectometry (GIXR). The chemical structures were revealed by Fourier transform infrared (FT-IR) analysis and compared with the macroscopic parameters. Low density and chemical imperfections were found in oxides formed in some chemical solutions ( HCl/H2O2, NH4OH/H2O2 and HNO3 solutions). The films with the most chemically homogeneous and densest oxide were prepared using H2SO4/H2O2 solution and ozonized water. The variations of the chemical structures were correlatively well explained in term of macroscopic parameters. We discuss the possible physical structures of native oxides based on the results of our experiments, as well as previous observations.