CPC H01L 29/42392 (2013.01) [H01L 21/30604 (2013.01); H01L 21/31111 (2013.01); H01L 21/31144 (2013.01); H01L 21/3212 (2013.01); H01L 29/0673 (2013.01); H01L 29/0847 (2013.01); H01L 29/1037 (2013.01); H01L 29/401 (2013.01); H01L 29/66545 (2013.01); H01L 29/66553 (2013.01); H01L 29/6656 (2013.01); H01L 29/66795 (2013.01); H01L 29/785 (2013.01)] | 20 Claims |
1. A method comprising:
forming a stack of semiconductor layers over a substrate, the stack of semiconductor layers including a first semiconductor layer and a second semiconductor layer;
forming a protective dielectric layer directly on the second semiconductor layer, wherein the forming of the protective dielectric layer directly on the second semiconductor layer includes:
forming a hard mask on the protective dielectric layer;
patterning the protective dielectric layer and the stack of semiconductor layers while using the hard mask as a mask; and
removing the hard mask;
forming a first gate dielectric layer directly on the protective dielectric layer;
removing the first gate dielectric layer to expose the protective dielectric layer;
removing a first portion of the second semiconductor layer;
forming a second gate dielectric layer directly on the protective dielectric layer and the first semiconductor layer; and
forming a gate electrode around the second gate dielectric layer.
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