US 5,310,451 A · 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.

Claims17

Dependent claims

A method of forming a semiconductor layer having ultra-high thickness uniformity and upon which semiconductor structures can subsequently be formed, comprising the steps of:

a) providing a primary substrate having a prescribed total thickness variation;
b) forming a stack upon said primary substrate for compressing thickness variation to be transferred into the semiconductor layer, said thickness variation compression stack comprising a first strain-free etch stop layer and at least one intermediate layer pair formed upon said first strain-free etch stop layer, said at least one intermediate layer pair each comprising a spacer layer and a subsequent strain-free etch stop layer formed upon said spacer layer;
c) forming an epitaxial silicon layer of a desired thickness upon said stack;
d) bonding said epitaxial silicon layer to a mechanical substrate to form a bonded substrate pair, said mechanical substrate having a prescribed total thickness variation and said bonded substrate pair having a combined total thickness variation equal to the sum of the respective total thickness variations of said primary and said mechanical substrates;
e) removing said primary substrate, wherein the combined thickness variation of said bonded substrate pair is transferred and compressed into said stack a first compression amount;
and
f) removing said stack, wherein the combined thickness variation of said 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 said first and second compression amounts.

5 more elements

A method of forming a Silicon-On-Insulator (SOI) semiconductor layer having ultra-high thickness uniformity and upon which semiconductor structures can subsequently be formed, comprising the steps of:

a) providing a primary substrate having a prescribed total thickness variation;
b) forming a stack upon said primary substrate for compressing thickness variation to be transferred into the SOI semiconductor layer, said thickness variation compression stack comprising a first strain-free etch stop layer having a dopant concentration of boron in the range of 1.times.10.sup.20 atoms/cm.sup.3 to 5.times.10.sup.20 atoms/cm.sup.3 compensated by 0.5% to 2.5% germanium, respectively, and at least one intermediate layer pair formed upon said first strain-free etch stop layer, said at least one intermediate layer pair each comprising a spacer layer and a subsequent strain-free etch stop layer having a dopant concentration of boron in the range of 1.times.10.sup.20 atoms/cm.sup.3 to 5.times.10.sup.20 atoms/cm.sup.3 compensated by 0.5% to 2.5% germanium, respectively, formed upon said spacer layer;
c) forming an epitaxial silicon layer of a desired SOI thickness upon said stack;
d) bonding said epitaxial silicon layer to a mechanical substrate to form a bonded substrate pair, said mechanical substrate having a prescribed total thickness variation and said bonded substrate pair having a combined total thickness variation equal to the sum of the respective total thickness variations of said primary and said mechanical substrates;
e) removing said primary substrate, wherein the combined thickness variation of said bonded substrate pair is transferred and compressed into said stack a first compression amount;
and
f) removing said stack, wherein the combined thickness variation of said 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 SOI semiconductor layer of ultra-high thickness uniformity, the thickness uniformity being a controlled function of said first and second compression amounts.

5 more elements

Dependencies are inferred from the claim text.

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

Life of this patent

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

Life of this patent

Abstract

Claims17