Gate all around device, method for manufacturing FinFET device, and method for manufacturing gate all around device
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsKai-Tai Chang, Tung-Ying Lee
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Abstract
In a method, a semiconductor substrate is etched to form a trench, such that the trench defines a channel portion. A hard mask layer is deposited over sidewalls of the channel portion. The semiconductor substrate is anisotropically etched to deepen the trench, such that the deepened trench further defines a base portion under the channel portion and the hard mask layer. The hard mask layer is removed from the sidewalls of the channel portion. The deepened trench is filled with an isolation material. The isolation material is recessed to form an isolation structure, in which the channel portion protrudes from the isolation structure.
Claims20
A method, comprising:
- forming a patterned hard mask and a patterned protective layer over a semiconductor substrate;
- etching a semiconductor substrate by using the patterned hard mask and the patterned protective layer as etching masks to form a trench, such that the trench defines a channel portion;
- depositing a hard mask layer over sidewalls of the channel portion and covering the patterned hard mask and the patterned protective layer such that a thickness of the hard mask layer is in a range from about 0.1 nm to about 10 nm;
- anisotropically etching the semiconductor substrate to deepen the trench, such that the deepened trench further defines a base portion under the channel portion and the hard mask layer, wherein anisotropically etching the semiconductor substrate comprises removing the patterned protective layer to expose the patterned hard mask;
- removing the hard mask layer from the sidewalls of the channel portion;
- filling the deepened trench with an isolation material;
- and
- recessing the isolation material to form an isolation structure, wherein the channel portion protrudes from the isolation structure.
A method, comprising:
- epitaxially growing a first film over a semiconductor substrate and a second film over the first film, wherein the first and second films are made of semiconductive materials;
- etching the first film and the second film to form a channel portion, wherein the channel portion has the etched first film and the etched second film;
- depositing a hard mask layer over sidewalls of the channel portion;
- anisotropically etching the semiconductor substrate to form a base portion under the channel portion and the hard mask layer such that a difference between a width of the base portion and a width of the channel portion is in a range from about 0.2 nm to about 20 nm;
- removing the hard mask layer from the sidewalls of the channel portion;
- forming an isolation structure around the base portion;
- and
- removing the etched first film from the channel portion.
A device, comprising:
- a semiconductor substrate having a protrusion structure, wherein the protrusion structure has a base portion and a channel portion over and spaced from the base portion such that the channel portion is not in contact with the base portion, a width of the base portion is greater than a width of the channel portion, and a difference between the width of the base portion and the width of the channel portion is in a range from about 0.2 nm to about 20 nm;
- an isolation structure around the base portion of the protrusion structure, wherein the channel portion of the protrusion structure protrudes from a top surface of the isolation structure;
- a gate dielectric layer over the channel portion of the protrusion structure;
- and
- a gate structure over the gate dielectric layer.
Dependencies are inferred from the claim text.