FinFETs with Gradient Germanium-Containing Channels
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsKuo-Cheng Ching, Zhiqiang Wu, Jiun-Jia Huang, Chao-Hsiung Wang, Chi-Wen Liu
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Abstract
A method includes forming a semiconductor fin, forming a dummy gate on a top surface and sidewalls of the semiconductor fin, and removing the dummy gate to form a recess. The semiconductor fin is exposed to the recess. After the dummy gate is removed, an oxidation is performed on the semiconductor fin to form a condensed germanium-containing fin in the recess, and a silicon oxide layer on a top surface and sidewalls of the condensed germanium-containing fin. The method further includes forming a gate dielectric over the condensed germanium-containing fin, and forming a gate electrode over the gate dielectric.
Claims21
A method comprising:
- forming a semiconductor fin;
- forming a dummy gate on a top surface and sidewalls of the semiconductor fin;
- removing the dummy gate to form a recess, wherein the semiconductor fin is exposed to the recess;
- after the removing the dummy gate, performing an oxidation on the semiconductor fin to form:
- a condensed germanium-containing fin in the recess;
- and
- a silicon oxide layer on a top surface and sidewalls of the condensed germanium-containing fin;
- forming a gate dielectric over the condensed germanium-containing fin;
- and
- forming a gate electrode over the gate dielectric.
A method comprising:
- forming isolation regions extending into a silicon substrate;
- performing an epitaxy to replace a portion of the silicon substrate between the isolation regions to form a silicon germanium strip;
- recessing the isolation regions, wherein a top portion of the silicon germanium strip over top surfaces of the recessed isolation regions forms a silicon germanium fin;
- forming a dummy gate stack on sidewalls and a top surface of the silicon germanium fin;
- forming a source/drain region on a side of the dummy gate stack;
- forming an Inter-Layer Dielectric (ILD) to cover the source/drain region;
- removing the dummy gate stack to form a recess in the ILD;
- and
- performing an oxidation on a portion of the silicon germanium fin exposed to the recess to form a condensed germanium-containing semiconductor fin.
-20. (canceled)
A method comprising:
- removing a dummy gate stack over a silicon germanium fin to form an opening in a dielectric layer, wherein a sidewall and a top surface of the silicon germanium fin are exposed after the removing the dummy gate stack;
- after the removing the dummy gate stack, performing an oxidation on the silicon germanium fin to form:
- a germanium-containing semiconductor fin;
- and
- a silicon oxide layer on an additional top surface and additional sidewalls of the germanium-containing semiconductor fin.
Dependencies are inferred from the claim text.