Gap-Filling Germanium Through Selective Bottom-Up Growth
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsDe-Wei Yu, Chien-Hao Chen, Ziwei Fang, Yee-Chia Yeo
Life of this patent
Estimating the term…
Abstract
A method includes depositing a silicon layer on a plurality of strips. The silicon layer is etched back to remove top portions of the silicon layer, and to expose some portions of the plurality of strips. Some bottom portions of the silicon layer at bottoms of trenches between the plurality of strips remain after the etching back. A germanium layer is selectively grown from remaining portions of the silicon layer, and exposed portions of the plurality of strips remain exposed after the germanium layer is selectively grown.
Claims20
A method comprising:
- depositing a first silicon layer on a plurality of strips, wherein trenches are between the plurality of strips;
- etching back the first silicon layer to remove top portions of the first silicon layer, and to expose some portions of the plurality of strips, wherein some bottom portions of the first silicon layer at bottoms of trenches remain after the etching back;
- and
- selectively growing a first germanium layer, wherein the first germanium layer is selectively grown from remaining portions of the first silicon layer, and exposed portions of the plurality of strips remain exposed after the first germanium layer is selectively grown.
A method comprising:
- forming source/drain regions based on a plurality of semiconductor fins, wherein the plurality of semiconductor fins is between a plurality of dummy gate stacks;
- forming a dielectric layer on the source/drain regions and the plurality of dummy gate stacks;
- depositing a first silicon layer on the dielectric layer;
- etching back the first silicon layer, with some portions of the first silicon layer remaining;
- growing a first germanium layer on the remaining portions of the first silicon layer;
- growing a second silicon layer on the first germanium layer;
- depositing a second germanium layer on the second silicon layer;
- performing a planarization to planarize the second germanium layer;
- replacing the plurality of dummy gate stacks with replacement gates;
- and
- removing the first silicon layer, the first germanium layer, the second silicon layer, and the second germanium layer.
A method comprising:
- forming a first strip group comprising a first plurality of strips and a second strip group comprising a second plurality of strips, wherein the first plurality of strips has first trenches therebetween, and the second plurality of strips has second trenches therebetween, and the first strip group is neighboring the second strip group, with a space therebetween being wider than spaces between the first trenches and spaces between the second trenches;
- depositing a first silicon layer on the first plurality of strips and the second plurality of strips;
- etching back the first silicon layer, with portions of the first silicon layer remaining at bottoms of the first trenches and the second trenches;
- and
- selectively growing a first germanium layer on the remaining portions of the first silicon layer, wherein the first germanium layer fully fills the first trenches and the second trenches, and the space has a portion unfilled by the first germanium layer.
Dependencies are inferred from the claim text.