Method of forming strained structures of semiconductor devices
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsCheng-Hsien Wu, Chih-Hsin Ko, Clement Hsingjen Wann
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Abstract
A method of fabricating a semiconductor device comprises providing a substrate with a shallow trench isolation (STI) within the substrate and a gate stack. A cavity is formed between the gate stack and the STI. The cavity comprises one sidewall formed by the STI, one sidewall formed by the substrate, and a bottom surface formed by the substrate. A film is grown in the cavity and thereafter an opening formed by removing a first portion of the strained film until exposing the bottom surface of the substrate while a second portion of the strained film adjoins the STI sidewall. Another epitaxial layer is then grown in the opening.
Claims20
A method of fabricating a semiconductor device, comprising:
- forming a shallow trench isolation (STI) within a semiconductor substrate;
- forming a gate stack over the semiconductor substrate;
- forming a cavity in the semiconductor substrate between the gate stack and the STI;
- growing an epitaxial film in the cavity, wherein the epitaxial film fills the cavity;
- defining an opening by etching a portion of the epitaxial film to expose a bottom surface of the cavity defined by the semiconductor substrate, wherein after the etching a first portion of the epitaxial film abuts a sidewall of the STI and a second portion of the epitaxial film extends the entire height of the sidewall of the opening adjacent the gate stack and opposing the STI and wherein the exposed bottom surface of the cavity extends from the first portion of the epitaxial film to the second portion of the epitaxial film;
- and
- epitaxially growing a semiconductor layer in the opening and on the exposed bottom surface.
A method, comprising:
- forming a gate stack on a major surface of a substrate and a shallow trench isolation (STI) disposed on one side of the gate stack;
- and
- etching a cavity in the substrate between the STI and the gate stack, wherein the cavity includes one sidewall formed by the STI, one sidewall formed by the substrate, and a bottom surface formed by the substrate;
- epitaxially growing a first strained film to fill the cavity;
- etching an opening in the first strained film to expose a surface of the substrate, wherein the sidewalls of the etched opening are defined by a first remaining portion of the first strained film and opposing the first remaining portion, a second remaining portion of the first strained film, wherein the first remaining portion of the first strained film has a top surface coplanar with the major surface of the substrate and wherein the exposed surface of the substrate extends between the first remaining portion and the second remaining portion;
- and
- filling the etched opening with a semiconductor layer, wherein the filling forms the semiconductor layer extending over a top surface of the remaining first portion and the remaining second portion of the first strained film.
A method, comprising:
- forming a gate stack on a major surface of a substrate and a shallow trench isolation (STI) disposed on one side of the gate stack;
- etching a cavity in the substrate between the STI and the gate stack;
- forming a first strained film such that it fills an entirety of the cavity;
- etching an opening in the first strained film to form an etched opening, wherein the etched opening has a bottom surface defined by the substrate and sidewalls defined by the first strained film the sidewalls defined by the first strained film extending to a top surface coplanar with the major surface of the substrate;
- and
- epitaxially growing SiGe within the etched opening such that the SiGe extends above a top surface of the first strained film and the STI.
Dependencies are inferred from the claim text.