Method of forming an ultra-uniform silicon-on-insulator layer

Abstract

A method of forming a thin semiconductor layer having ultra-high thickness uniformity and upon which semiconductor structures can subsequently be formed is disclosed. The method comprises providing a primary substrate having a prescribed total thickness variation (TTV). A stack is formed upon the primary substrate for compressing thickness variation to be transferred into the thin semiconductor layer. An epitaxial silicon layer of a desired SOI thickness is formed upon the stack. The epitaxial silicon layer is then bonded to a mechanical substrate to form a bonded substrate pair, the mechanical substrate having a prescribed TTV and the bonded substrate pair having a combined TTV equal to the sum of the TTVs of the primary and mechanical substrates, respectively. The primary substrate is subsequently removed, wherein the combined TTV of the bonded substrate pair is transferred and compressed into the stack by a first compression amount. The stack is thereafter removed, wherein the combined TTV of the bonded substrate pair is further transferred and compressed a second compression amount into said epitaxial silicon layer, whereby said epitaxial silicon layer remains on said mechanical substrate to form the semiconductor layer of ultra-high thickness uniformity, the thickness uniformity being a controlled function of the first and second compression amounts.