Replacement metal gate stack for diffusion prevention
First Claim
1. A method of forming a semiconductor structure, the method comprising:
- depositing a gate dielectric layer lining a recess of a gate structure formed on a substrate, a first portion of the gate dielectric layer covering sidewalls of the recess and a second portion of the gate dielectric layer covering a bottom of the recess;
depositing a protective layer above the gate dielectric layer, the protective layer substantially filling the recess;
recessing the protective layer selectively to the gate dielectric layer, wherein a top surface of the protective layer is below of the recess;
recessing the first portion of the gate dielectric layer until a top of the first portion of the gate dielectric layer is approximately coplanar with the top surface of the protective layer, wherein the protective layer protects the second portion of the gate dielectric layer while recessing the first portion of the gate dielectric layer;
removing the protective layer;
depositing a conductive barrier above the recessed first portion of the gate dielectric layer;
depositing a metal gate above the conductive barrier; and
forming a capping layer above the metal gate, wherein the conductive barrier separates the capping layer from the recessed first portion of the gate dielectric layer.
1 Assignment
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Accused Products
Abstract
A method of forming a semiconductor structure includes depositing a gate dielectric layer lining a recess of a gate structure formed on a substrate with a first portion of the gate dielectric layer covering sidewalls of the recess and a second portion of the gate dielectric layer covering a bottom of the recess. A protective layer is deposited above the gate dielectric layer and then recessed selectively to the gate dielectric layer so that a top surface of the protective layer is below of the recess. The first portion of the gate dielectric layer is recessed until a top of the first portion of the gate dielectric layer is approximately coplanar with the top surface of the protective layer. The protective layer is removed and a conductive barrier is deposited above the recessed first portion of the gate dielectric layer to cut a diffusion path to the gate dielectric layer.
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Citations
8 Claims
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1. A method of forming a semiconductor structure, the method comprising:
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depositing a gate dielectric layer lining a recess of a gate structure formed on a substrate, a first portion of the gate dielectric layer covering sidewalls of the recess and a second portion of the gate dielectric layer covering a bottom of the recess; depositing a protective layer above the gate dielectric layer, the protective layer substantially filling the recess; recessing the protective layer selectively to the gate dielectric layer, wherein a top surface of the protective layer is below of the recess; recessing the first portion of the gate dielectric layer until a top of the first portion of the gate dielectric layer is approximately coplanar with the top surface of the protective layer, wherein the protective layer protects the second portion of the gate dielectric layer while recessing the first portion of the gate dielectric layer; removing the protective layer; depositing a conductive barrier above the recessed first portion of the gate dielectric layer; depositing a metal gate above the conductive barrier; and forming a capping layer above the metal gate, wherein the conductive barrier separates the capping layer from the recessed first portion of the gate dielectric layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification