Local thinning of semiconductor fins
First Claim
1. A method of forming a semiconductor structure comprising:
- forming a semiconductor fin on a substrate;
forming a planarization dielectric layer over said semiconductor fin, wherein a first portion of a top surface of said semiconductor fin is not covered with said planarization dielectric layer, and a second portion of said top surface of said semiconductor fin is covered with said planarization dielectric layer;
converting said first portion of said top surface of said semiconductor fin into a semiconductor oxide portion employing an oxygen cluster implantation process in which clusters of oxygen atoms are implanted into said first portion of said semiconductor fin; and
removing said semiconductor oxide portion,wherein said first portion corresponds to an active region of said semiconductor fin, and said second portion corresponds to a body region of said semiconductor fin.
6 Assignments
0 Petitions
Accused Products
Abstract
After formation of gate structures over semiconductor fins and prior to formation of raised active regions, a directional ion beam is employed to form a dielectric material portion on end walls of semiconductor fins that are perpendicular to the lengthwise direction of the semiconductor fins. The angle of the directional ion beam is selected to be with a vertical plane including the lengthwise direction of the semiconductor fins, thereby avoiding formation of the dielectric material portion on lengthwise sidewalls of the semiconductor fins. Selective epitaxy of semiconductor material is performed to grow raised active regions from sidewall surfaces of the semiconductor fins. Optionally, horizontal portions of the dielectric material portion may be removed prior to the selective epitaxy process. Further, the dielectric material portion may optionally be removed after the selective epitaxy process.
22 Citations
13 Claims
-
1. A method of forming a semiconductor structure comprising:
-
forming a semiconductor fin on a substrate; forming a planarization dielectric layer over said semiconductor fin, wherein a first portion of a top surface of said semiconductor fin is not covered with said planarization dielectric layer, and a second portion of said top surface of said semiconductor fin is covered with said planarization dielectric layer; converting said first portion of said top surface of said semiconductor fin into a semiconductor oxide portion employing an oxygen cluster implantation process in which clusters of oxygen atoms are implanted into said first portion of said semiconductor fin; and removing said semiconductor oxide portion, wherein said first portion corresponds to an active region of said semiconductor fin, and said second portion corresponds to a body region of said semiconductor fin. - View Dependent Claims (2, 3, 4, 5, 6)
forming a gate cavity by removing said disposable gate structure selective to said planarization dielectric layer, wherein said first portion of said top surface of said semiconductor fin is formed underneath said gate cavity.
-
-
3. The method of claim 2, further comprising:
-
forming another semiconductor fin on said substrate; and masking said another semiconductor fin with a combination of a patterned masking layer and said planarization dielectric layer during said oxygen cluster implantation process.
-
-
4. The method of claim 3, wherein said disposable gate structure is formed across said another semiconductor fin, and said patterned masking layer does not cover a region of said gate cavity that overlies said semiconductor fin and covers another region of said gate cavity that overlies said another semiconductor fin.
-
5. The method of claim 2, further comprising
forming a gate spacer around said disposable gate stack prior to formation of said planarization dielectric layer, wherein said gate spacer blocks said clusters of oxygen atoms during said oxygen cluster implantation process. -
6. The method of claim 1, further comprising forming a stack of a gate dielectric and a gate electrode directly on a surface of said semiconductor fin from which said semiconductor oxide portion is removed.
-
7. A method of forming a semiconductor structure comprising:
-
forming a plurality of semiconductor fins including two outermost semiconductor fins on a substrate; forming semiconductor oxide portions on outermost sidewalls of said plurality of semiconductor fins employing an oxygen cluster implantation process in which clusters of oxygen atoms are implanted into physically exposed and unshaded surface portions of said two outermost semiconductor fins while inner sidewalls of said two outermost semiconductor fins are at least partially shaded; and laterally thinning said two outermost semiconductor fins by removing said semiconductor oxide portions. - View Dependent Claims (8, 9, 10, 11, 12, 13)
-
Specification