Uniform bottom spacer for vertical field effect transistor
First Claim
1. A method of forming a semiconductor structure, the method comprising:
- forming a protective liner above and in direct contact with a semiconductor substrate, a fin extending upward from the semiconductor substrate and a nitride-oxide-nitride hardmask positioned on top of the fin, wherein the protective liner comprises a metal oxide material;
removing the protective liner from a top surface of the semiconductor substrate and a top surface of the nitride-oxide-nitride hardmask, wherein the protective liner remains on sidewalls of the fin and the nitride-oxide-nitride hardmask;
forming a first dielectric layer above and in direct contact with the semiconductor substrate, the protective liner and the top surface of the nitride-oxide-nitride hardmask;
simultaneously removing top portions of the first dielectric layer and the nitride-oxide-nitride hardmask, wherein the first dielectric layer remains in direct contact with a bottom portion of the protective liner and the semiconductor substrate;
removing the protective liner from the semiconductor structure, wherein removing the protective liner creates an opening between the first dielectric layer and the bottom portion of the fin; and
forming a second dielectric layer, the second dielectric layer fills the opening between the first dielectric layer and the bottom portion of the fin.
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Accused Products
Abstract
A method of forming a semiconductor structure includes forming a protective liner comprising a metal oxide above and in direct contact with a semiconductor substrate, a fin extending upward from the semiconductor substrate and a NON hardmask positioned on top of the fin, removing the protective liner from top surfaces of the semiconductor substrate and NON hardmask, the protective liner remaining on sidewalls of the fin and the NON hardmask, depositing a first dielectric layer, simultaneously removing top portions of the first dielectric layer and NON hardmask, the first dielectric layer remains in direct contact with a bottom portion of the protective liner and the semiconductor substrate, removing the protective liner, the removing of the protective liner creates an opening between the first dielectric layer and the bottom portion of the fin that is subsequently filled with a second dielectric layer.
15 Citations
17 Claims
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1. A method of forming a semiconductor structure, the method comprising:
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forming a protective liner above and in direct contact with a semiconductor substrate, a fin extending upward from the semiconductor substrate and a nitride-oxide-nitride hardmask positioned on top of the fin, wherein the protective liner comprises a metal oxide material; removing the protective liner from a top surface of the semiconductor substrate and a top surface of the nitride-oxide-nitride hardmask, wherein the protective liner remains on sidewalls of the fin and the nitride-oxide-nitride hardmask; forming a first dielectric layer above and in direct contact with the semiconductor substrate, the protective liner and the top surface of the nitride-oxide-nitride hardmask; simultaneously removing top portions of the first dielectric layer and the nitride-oxide-nitride hardmask, wherein the first dielectric layer remains in direct contact with a bottom portion of the protective liner and the semiconductor substrate; removing the protective liner from the semiconductor structure, wherein removing the protective liner creates an opening between the first dielectric layer and the bottom portion of the fin; and forming a second dielectric layer, the second dielectric layer fills the opening between the first dielectric layer and the bottom portion of the fin. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of forming a semiconductor structure, the method comprising:
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forming a fin extending upward from a semiconductor substrate; forming a nitride-oxide-nitride hardmask above and in direct contact with the fin, the nitride-oxide-nitride hardmask comprising a first layer in direct contact with the fin, a second layer above and in direct contact with the first layer, and a third layer above and in direct contact with the second layer; conformally depositing a protective liner above and in direct contact with the semiconductor substrate and the fin, the protective liner comprising a metal oxide material; removing the protective liner from a top surface of the semiconductor substrate and a top surface of the third layer of the nitride-oxide-nitride hardmask, wherein the protective liner remains on sidewalls of the fin and the nitride-oxide-nitride hardmask; depositing a first dielectric layer above and in direct contact with the semiconductor substrate, the protective liner and the top surface of the third layer; simultaneously removing top portions of the first dielectric layer and the third layer of the nitride-oxide-nitride hardmask, the first dielectric layer and the third layer comprise substantially similar materials, wherein the first dielectric layer remains in direct contact with a bottom portion of the protective liner and the semiconductor substrate; removing the protective liner from the semiconductor structure, wherein removing the protective liner creates an opening between the first dielectric layer and the bottom portion of the fin; conformally depositing a second dielectric layer, the second dielectric layer fills the opening between the first dielectric layer and the bottom portion of the fin; and etching the second dielectric layer until a top surface of the second dielectric layer is coplanar with a top surface of the first dielectric layer such that a thickness of the first dielectric layer and a thickness of the second dielectric layer are substantially the same, wherein the first dielectric layer and the second dielectric layer comprise a bottom spacer. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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Specification