Patent ID: 7816237
Filing Date: 2010-10-19
Classification: H01L

Abstract:
1. A method of forming a field effect transistor, said method comprising: providing a silicon substrate having a top surface; increasing the oxygen content at said top surface of said silicon substrate as compared to other portions of said silicon substrate below said top surface; after said increasing of said oxygen content, epitaxially growing an epitaxial silicon layer on said top surface of said silicon substrate; forming a gate stack on said epitaxial silicon layer; and delivering dopants into regions of said epitaxial silicon layer not protected by said gate stack, wherein said increasing of said oxygen content is performed so that said oxygen content is increased above an amount required to substantially limit said dopants from moving through said top surface into said silicon substrate during and after said delivering and still below an amount that would prevent said epitaxially growing of said epitaxial silicon layer.