X-RAY REFLECTOMETRY AND INFRARED-ANALYSIS OF NATIVE OXIDES ON SI(100)FORMED BY CHEMICAL TREATMENT

We investigated native-oxide formation on Si(100) in some cleaning sol utions. The macroscopic density and thickness of the native oxides wer e determined by glancing incidence X-ray reflectometry (GIXR). The che mical structures were revealed by Fourier transform infrared (FT-LR) a nalysis and compared with the macroscopic parameters. Low density and chemical imperfections were found in oxides formed in some chemical so lutions (HCl/H2O2, NH4OH/H2O2 and HNO3 solutions). The films with the most chemically homogeneous and densest oxide were prepared using H2SO 4/H2O2 solution and ozonized water. The variations of the chemical str uctures were correlatively well explained in term of macroscopic param eters. We discuss the possible physical structures of native oxides ba sed on the results of our experiments, as well as previous observation s.