Bulk and strained silicon on insulator using local selective oxidation
AssigneeInternational Business Machines Corporation
InventorsJack Oon Chu, Khalid Ezzeldin Ismail, Kim Yang Lee, John Albrecht Ott
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Abstract
A method for forming buried oxide regions below a single crystal semiconductor layer incorporating the steps of forming epitaxial layers having different rates of oxidation with the lower layer having a faster rate of oxidation and oxidizing the layers through an opening in a mask. A plurality of oxide isolated FET's may be formed. The invention reduces the problem of source/drain parasitic capacitance and short channel effects while isolating FET's and eliminating floating body effects of an FET by selectively oxidizing semiconductor layers.
Claims24
A method for forming buried oxide regions below a region of a single crystal semiconductor layer comprising the steps of:
- selecting a single crystal silicon substrate,
- forming a first epitaxial layer selected from the group consisting of Si.sub.1-x Ge.sub.x and (Si.sub.(1-x) Ge.sub.x).sub.a C.sub.1-a on the upper surface of said substrate, said first layer epitaxial having a first rate of oxidation,
- forming a second epitaxial layer containing silicon on said first epitaxial layer, said second epitaxial layer having a second rate of oxidation less than said first rate of oxidation,
- forming a mask over said second epitaxial layer,
- patterning said mask to form mask openings in said mask, and
- oxidizing through said mask openings said second epitaxial layer and said first epitaxial layer whereby a plurality of oxide regions form in said first and second epitaxial layers with portions of said oxide regions replacing portions of said first epitaxial layer underneath said second epitaxial layer.
Dependencies are inferred from the claim text.