HIGH-QUALITY SGOI BY ANNEALING NEAR THE ALLOY MELTING POINT

摘要

A method of forming a low-defect, substantially relaxed SiGe-on-insulator substrate material is proveded. The method includes first forming a Ge-containing layer on a surface of a first single crystal Si layer which is present atop a barrier layer that is resistant to Ge diffusion. A heating step is then performed at a temperature that approaches the melting point of the final SiGe alloy and retards the formation of Ge throughout the first single crystal Si layer and the Ge-containing layer thereby forming a substantially relaxed, single crystal SiGe layer atop the barrier layer. Moreover, because the heating step is carried out at a temperature that approaches the melting point of the final SiGe alloy, defects that persist in the single crystal SiGe layer as a result of relaxation are efficiently annihilated therefrom. In one embodiment, the heating step includes an oxidation process that is performed at a temperature from about 1230° to about 1320°C for a time period of less than about 2 hours. This embodiment provides SGOI substrate that have minimal surface pitting and reduced crosshatching.