Interfacial investigation of in situ oxidation of 4H-SiC

An in situ oxidation study of root3 x root3 R30 degrees reconstructed 4H-Si C(0001) surfaces is reported. An intermediate oxidation state (interpreted to be Si+1) is revealed in core level photoemission spectra recorded from t he in situ prepared SiO2/4H-SiC samples. Oxidation was made at a pressure o f similar to 10(-3) Torr in flowing oxygen and at substrate temperatures fr om 600 degreesC to 950 degreesC. The highest oxidation rate was obtained at 800 degreesC when approximate to 25 Angstrom thick SiO2 layers were prepar ed. The surface related C 1s components observed on the clean reconstructed 4H-SiC(0001) surfaces were found to disappear after oxidation. No carbon o r carbon containing by-product at the interface or in the oxide were possib le to observe for the films grown. (C) 2001 Elsevier Science B.V. All right s reserved.