CPC H01L 29/785 (2013.01) [H01L 21/3065 (2013.01); H01L 21/324 (2013.01); H01L 21/823431 (2013.01); H01L 21/823821 (2013.01); H01L 21/845 (2013.01); H01L 29/0649 (2013.01); H01L 29/0653 (2013.01); H01L 29/1037 (2013.01); H01L 29/16 (2013.01); H01L 29/161 (2013.01); H01L 29/66795 (2013.01); H01L 29/66818 (2013.01); H01L 29/7851 (2013.01)] | 20 Claims |
1. A method comprising:
providing a substrate having thereon a layer of epitaxial channel material;
patterning a hardmask above the layer of epitaxial channel material;
performing a first etch to a first depth, using the hardmask as a mask, to form an upper portion of a fin, wherein the first depth extends beyond a bottom surface of the layer of epitaxial channel material;
forming a liner over exposed surfaces of the upper portion of the fin;
performing a second etch to a second depth, using the liner as a mask, to form a lower portion of the fin;
removing the liner; and
forming a gate dielectric on exposed surfaces of the upper portion of the fin, wherein the gate dielectric extends beyond the bottom surface of the layer of epitaxial channel material.
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