Non-planar transistors with replacement fins and methods of forming the same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorKa-Hing Fung
Life of this patent
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Abstract
A method includes forming a first semiconductor fin, and oxidizing surface portions of the first semiconductor fin to form a first oxide layer. The first oxide layer includes a top portion overlapping the first semiconductor fin and sidewall portions on sidewalls of the first semiconductor fin. The top portion of the first oxide layer is then removed, wherein the sidewall portions of the first oxide layer remains after the removing. The top portion of the first semiconductor fin is removed to form a recess between the sidewall portions of the first oxide layer. An epitaxy is performed to grow a semiconductor region in the recess.
Claims20
A method comprising:
- forming a first, a second, and a third semiconductor fin;
- simultaneously oxidizing sidewall portions of the first, the second, and the third semiconductor fins to form a first, a second, and a third oxide layer, respectively;
- replacing a top portion of the first semiconductor fin with a first replacement fin;
- replacing a top portion of the second semiconductor fin with a second replacement fin;
- removing the first and the second oxide layers without removing the third oxide layer;
- forming a first gate dielectric on a top surface and sidewalls of the first replacement fin;
- forming a second gate dielectric on a top surface and sidewalls of the second replacement fin;
- and
- forming a third gate dielectric on a top surface and sidewalls of the third oxide layer.
A method comprising:
- forming a silicon fin protruding higher than Shallow Trench Isolation (STI) regions, wherein the STI regions comprise portions on opposite sides of the silicon fin;
- oxidizing a top surface portion and sidewall surface portions of the silicon fin to form a first silicon oxide layer;
- forming a mask layer comprising:
- sidewall portions on sidewalls of the first silicon oxide layer;
- and
- a top portion overlapping the first silicon oxide layer;
- forming a second silicon oxide layer filling recesses that extend into the mask layer, wherein a top portion of the mask layer that overlaps the silicon fin is exposed;
- etching the top portion of the mask layer and a top portion of the first silicon oxide layer to expose the silicon fin;
- removing a top portion of the silicon fin to form a recess;
- and
- re-growing a replacement fin in the recess.
A method comprising:
- forming a first, a second, and a third semiconductor fin;
- oxidizing sidewall portions of the first, the second, and the third semiconductor fins to form a first, a second, and a third oxide layer, respectively;
- replacing a top portion of the first semiconductor fin with a first replacement fin, wherein the replacing the top portion of the first semiconductor fin comprises:
- removing a top portion of the first oxide layer covering the first semiconductor fin;
- etching the top portion of the first semiconductor fin to form a recess between remaining sidewall portions of the first oxide layer;
- and
- growing the first replacement fin in the recess;
- replacing a top portion of the second semiconductor fin with a second replacement fin;
- removing the first and the second oxide layers without removing the third oxide layer;
- forming a first gate dielectric on a top surface and sidewalls of the first replacement fin;
- forming a second gate dielectric on a top surface and sidewalls of the second replacement fin;
- and
- forming a third gate dielectric on a top surface and sidewalls of the third oxide layer.
Dependencies are inferred from the claim text.