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US 12,191,206 B2Granted
Method of manufacturing fin spacers having different heights using a polymer-generating etching process
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorYu-Lien Huang
Life of this patent
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Abstract
A method includes forming a gate stack on a plurality of semiconductor fins. The plurality of semiconductor fins includes a plurality of inner fins, and a first outer fin and a second outer fin on opposite sides of the plurality of inner fins. Epitaxy regions are grown based on the plurality of semiconductor fins, and a first height of the epitaxy regions measured along an outer sidewall of the first outer fin is smaller than a second height of the epitaxy regions measured along an inner sidewall of the first outer fin.
Claims20
A method comprising:
- forming isolation regions over a bulk semiconductor substrate;
- recessing the isolation regions, wherein top portions of semiconductor strips between the isolation regions protrude higher than top surfaces of the isolation regions to form a fin group comprising a plurality of fins, and wherein the plurality of fins comprise:
- a plurality of inner fins;
- and
- a first outer fin and a second outer fin on opposite sides of the plurality of inner fins;
- forming fin spacers on sidewalls of the plurality of fins, wherein the fin spacers comprise inner fin spacers, and outer fin spacers having greater heights than the inner fin spacers, and wherein the forming the fin spacers comprises:
- depositing a spacer layer on the plurality of fins;
- and
- performing a first etching process on the spacer layer, wherein in the first etching process, a first polymer layer is generated on the spacer layer;
- and
- removing the first polymer layer, wherein at a time after the first polymer layer is removed, the spacer layer comprises thinned portions covering top surfaces of the plurality of fins.
8 more elements
A method comprising:
- forming isolation regions extending into a semiconductor substrate;
- forming a plurality of semiconductor fins protruding higher than the isolation regions, wherein the plurality of semiconductor fins comprise:
- a first outer fin and a second outer fin;
- and
- an inner fin between the first outer fin and the second outer fin;
- depositing a spacer layer on top surfaces and sidewalls of the plurality of semiconductor fins;
- forming fin spacers comprising outer fin spacers and inner fin spacers from the spacer layer, wherein the outer fin spacers on outer sidewalls of the first outer fin and the second outer fin are higher than the inner fin spacers on sidewalls of the inner fin, and wherein the forming the fin spacers comprises:
- performing a first etching process to thin the spacer layer, wherein the first etching process comprises applying an etching chemical to be in contact with the spacer layer;
- after the spacer layer is thinned, removing a first polymer layer generated in the first etching process, wherein the first polymer layer starts to be generated at a time after the etching chemical has been in contact with the spacer layer;
- and
- epitaxially growing epitaxy regions based on the plurality of semiconductor fins.
8 more elements
A method comprising:
- depositing a spacer layer on top surfaces and sidewalls of a plurality of protruding fins, wherein the plurality of protruding fins comprise:
- a first outer fin and a second outer fin;
- and
- an inner fin between the first outer fin and the second outer fin;
- etching the spacer layer to form fin spacers on sidewalls of the plurality of protruding fins, wherein the fin spacers comprise:
- a first fin spacer on an outer sidewall of the first outer fin, wherein the first fin spacer has a first height;
- and
- a second fin spacer on an inner sidewall of the first outer fin, wherein the second fin spacer has a second height smaller than the first height, and wherein the etching the spacer layer comprises performing a cycle comprising:
- performing an etching process to etch the spacer layer, wherein a polymer layer is generated at a same time the spacer layer is etched, and is generated as a by-product of the etching process;
- and
- after the etching process, removing the polymer layer generated in the etching process.
8 more elements
Dependencies are inferred from the claim text.