Reduction of the interfacial Si displacement of ultrathin SiO₂ film on Si(100) formed by highly-concentrated ozone

To investigate the interfacial Si-displacement of an ultrathin silicon dioxide formed by oxidation of a Si(100) substrate with atmospheric-pressure ozone at a substrate temperature of 375 °C, we examined the structure around the interface of SiO₂ and Si using medium-energy ion scattering spectroscopy (MEIS). A thermally grown oxide with the same thickness as an ozone-formed oxide was also measured with MEIS for comparison. The ozone-formed oxide film exhibited considerably less Si-displacement in the oxide layers near the interface than a thermally grown oxide film, which indicates that an ozone oxide film is homogenous. These results explain well our previous findings that an ozone oxide film exhibits a constant HF etching rate while a thermally grown oxide film slows the etching rate near the interface.