SILICON SURFACE IMPERFECTION PROBED WITH A NOVEL X-RAY-DIFFRACTION TECHNIQUE AND ITS INFLUENCE ON THE RELIABILITY OF THERMALLY GROWN SILICON-OXIDE

Silicon surface imperfection was investigated by an X-ray diffraction technique under the condition of simultaneous specular and Bragg refle ctions, using the tunability of synchrotron radiation in conjunction w ith an asymmetric reflection. The surface roughness was the main imper fection on the conventional mechanochemical polished silicon wafer, an d this surface imperfection was reduced by a series of sacrificial oxi dation procedures. The time-dependent dielectric breakdown (TDDB) char acteristics were also improved by these procedures. In this way, the r eliability of the metal oxide semiconductor capacitor was dependent on the surface imperfection of the silicon substrate.