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US 7,396,773 B1Granted
Method for cleaning a gate stack
AssigneeCypress Semiconductor Corporation
InventorsAlain Blosse, Krishnaswamy Ramkumar
Life of this patent
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Abstract
A method of making a semiconductor structure, comprises cleaning a gate stack with a cleaning solution. The gate stack comprises a gate layer, a metallic layer on the gate layer, and a etch-stop layer on the metallic layer. The gate layer is on a semiconductor substrate, the cleaning solution is a non-oxidizing cleaning solution, and the metallic layer comprises an easily oxidized metal.
Claims22
A method of making a semiconductor structure, comprising:
- cleaning a gate stack with a cleaning solution;
- wherein the gate stack comprises a gate layer, a metallic layer on the gate layer, and an etch-stop layer on the metallic layer,
- the gate layer is on a semiconductor substrate,
- the cleaning solution is a non-oxidizing cleaning solution,
- the metallic layer comprises an easily oxidized metal, and
- the cleaning solution consists essentially of:
- (a) at least one member selected from the group consisting of an amino alcohol and amino ether,
- (b) at least one member selected from the group consisting of an aromatic alcohol, aliphatic polyol, and aliphatic polyol ether, and
- (c) a hydroxyl amine.
6 more elements
A method of making a semiconductor structure, comprising:
- cleaning a gate stack comprising a metallic layer with a solution;
- wherein the metallic layer is on a gate layer,
- the gate layer is on a semiconductor substrate,
- an etch-stop layer is on the metallic layer,
- the metallic layer comprises tungsten and has a thickness of at most 450 angstroms, and
- the cleaning solution consists essentially of:
- (a) an amino alkoxy alcohol having 2-12 carbon atoms,
- (b) an aromatic diol or triol, and
- (c) hydroxylamine or an alkylhydroxylamine containing 1-6 carbon atoms.
6 more elements
A method of making a semiconductor structure, comprising:
- removing photoresist;
- wherein the photoresist is on a etch-stop layer,
- the etch-stop layer is on a metallic layer,
- the metallic layer has a thickness of at most 450 angstroms and is on a gate layer,
- the gate layer is on a semiconductor substrate, and
- the removing comprises ashing and applying a cleaning solution consisting essentially of:
- (a) at least one member selected from the group consisting of an amino alcohol and amino ether,
- (b) at least one member selected from the group consisting of an aromatic alcohol, aliphatic polyol, and aliphatic polyol ether, and
- (c) a hydroxylamine.
6 more elements
Dependencies are inferred from the claim text.