GeSi [sbnd]Si strained layer superlattices grown by low-pressure CVD

Abstract

SiGe Si and Si Ge strained-layer superlattices were grown by a low-pressure CVD system (LP-CVD) using Si 2H 6 (or Si 3H 8) and GeH 4. Their characteristics were studied using TEM observations, X-ray diffraction, AES, RBS, and Raman scattering measurements. It was found that for producing SiGe Si SLS's, the superlattice periodicity could be controlled in the range of several to several hundredångströms. It is concluded that interfaces between the SiGe and Si layers are very sharp. The thickness of the interface region, where the Ge content changes, is less than 10Å. On the other hand, for producing Si Ge SLS's, intermixing of Si and Ge atoms was an inevitable problem. It was, however, found that decreasing the growth temperature reduces effectively the intermixing.