Method of manufacturing a strained silicon on a SiGe on SOI substrate
AssigneeInternational Business Machines Corporation
InventorsKangguo Cheng, Dureseti Chidambarrao
Life of this patent
Estimating the term…
Abstract
A semiconductor device with an undercut relaxed SiGe layer having voids beneath the SiGe layer. The voids may be filled with a dielectric such as SiO2. A strained Si layer may be epitaxially grown on the relaxed SiGe layer to combine the benefits of a defect-free strained Si surface and a silicon-on-insulator substrate. The relaxed SiGe layer may be relatively thin, with a thickness below the critical thickness. Thus, the structure accommodates shallow junctions, which exhibit reduced junction capacitance.
Claims26
A method of fabricating a semiconductor structure, comprising the steps of:
- forming a Si1-xGex layer on a multi-layer substrate;
- forming a plurality of channels in the Si1-xGex layer and in a top layer of the multi-layer substrate;
- after forming the plurality of channels, removing the top layer of the multi-layer substrate underneath the Si1-xGex layer to form a void defined by an undercut border in the multi-layer substrate;
- and
- filling the channels and the void with a dielectric material.
A method of fabricating a semiconductor structure, comprising:
- forming a Si1-xGex layer on a substrate;
- forming a plurality of channels in the Si1-xGex layer and the substrate;
- and
- after forming the plurality of channels, removing a layer of the multi-layer substrate underneath the Si1-xGex layer to form a void defined by an undercut border in the substrate.
A method, comprising:
- forming a Si1-xGex layer on a multi-layered substrate;
- forming a plurality of channels in the Si1-xGex layer and the substrate;
- after forming the plurality of channels, removing a top layer of the multi-layer substrate underneath the Si1-xGex layer to form a void defined by an undercut border in the multi-layer substrate;
- removing a portion of the multi-layered substrate underneath the Si1-xGex layer to form a void;
- and
- producing a relaxed portion of the Si1-xGex layer above the void.
Dependencies are inferred from the claim text.