US6656852B2
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US
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Method for the selective removal of high-k dielectrics
Assignee: Texas Instruments Inc
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Filing: 2001-12-06
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Granted: 2003-12-02
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Expires: 2021-12-06
Abstract
Abstract One aspect of the invention relates to a method of etching a high-k dielectric. The method involves removing an exposed portion of a high-k dielectric layer from a substrate by wet etching with a solution comprising water, a strong acid, an oxidizing agent, and a fluorine compound. The etching solution provides selectivity towards the high-k film against insulating materials and polysilicon and is therefore useful in manufacturing FETs.
Inventors
- 👤 Antonio Luis Pacheco Rotondaro
- 👤 James Joseph Chambers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:13
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01332; H10D64/01336; H10D64/01342; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10D64/60; H10D64/66; H10D64/68; H10D64/691; H10D64/693
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
57 words
A method of removing an exposed portion of a high-k dielectric layer from a substrate, comprising: providing a substrate with a high-k dielectric layer; wet etching with a final etching solution consisting essentially of water, a strong acid, an oxidizing agent, and a fluorine compound; wherein the strong acid is not the same as the fluorine compound.
Claim 2
Independent Claim
57 words
A method of removing an exposed portion of a high-k dielectric layer from a substrate, comprising: providing a substrate with a high-k dielectric layer; wet etching with a final etching solution consisting essentially of water, a strong acid, an oxidizing agent, and a fluorine compound; wherein the strong acid is not the same as the fluorine compound.
Claim 3
Dependent Claim
18 words
The method of claim 1 , wherein the high-k dielectric layer is at least about 1 nm thick.
Claim 4
Dependent Claim
13 words
The method of claim 1 , wherein the strong acid is sulfuric acid.
Claim 5
Dependent Claim
13 words
The method of claim 1 , wherein the oxidizing agent is hydrogen peroxide.
Claim 6
Dependent Claim
13 words
The method of claim 1 , wherein the fluorine compound is hydrofluoric acid.
Claim 7
Dependent Claim
25 words
The method of claim 1 , wherein the strong acid is sulfuric acid, oxidizing agent is hydrogen peroxide, and the fluorine compound is hydrofluoric acid.
Claim 8
Dependent Claim
48 words
The method of claim 1 , further comprising etching with a first etching solution to remove a bulk portion of the exposed portion of the high-k dielectric prior to wet etching with the final etching solution, wherein the first etching solution is different from the final etching solution.
Claim 9
Dependent Claim
18 words
The method of claim 7 , wherein the first wet etching solution consists essentially of dilute hydrofluoric acid.
Claim 10
Dependent Claim
14 words
The method of claim 1 , wherein the substrate comprises islands of oxide insulator.
Claim 11
Dependent Claim
28 words
The method of claim 9 , wherein the islands of oxide insulator comprise a material selected from the group consisting of silicon oxide, TEOS and a combination thereof.
Claim 12
Dependent Claim
13 words
The method of claim 1 , wherein the high-k dielectric comprises a silicate.
Claim 13
Dependent Claim
14 words
The method of claim 1 , wherein the high-k dielectric comprises a metal oxide.
Claim 14
Dependent Claim
13 words
The method of claim 1 , wherein the high-k dielectric comprises an aluminate.
Claim 15
Dependent Claim
18 words
The method of claim 1 , wherein the high-k dielectric comprises an metal oxynitride or a metal-silicon oxynitride.
Claim 16
Dependent Claim
21 words
The method of claim 1 , wherein the substrate comprises a polysilicon layer patterned over a layer of the high-k dielectric.
Claim 17
Dependent Claim
13 words
The method of claim 1 , wherein the substrate comprises a silicon wafer.
Claim 18
Dependent Claim
47 words
A method of manufacturing a field effect transistor, comprising: forming isolation regions; forming a gate layer comprising a high-k dielectric; forming a poly layer; patterning the poly layer; and patterning the gate layer; wherein the gate layer is patterned using a process according to claim 1 .
Claim 19
Independent Claim
104 words
A method of etching high-k dielectric, comprising: providing high-k dielectric material; etching with a first solution comprising a first strong acid to remove a bulk portion of the high-k dielectric; etching with a second solution comprising water, a second strong acid, an oxidizing agent, and a fluorine compound to remove a second portion of the high-k dielectric; wherein the first solution is not the same as the second solution, the second strong acid is not the same as the fluorine compound, and the second portion of the high-k dielectric is at least {fraction (1/10)}th the thickness of the bulk potion of the high-k dielectric.
Claim 20
Independent Claim
104 words
A method of etching high-k dielectric, comprising: providing high-k dielectric material; etching with a first solution comprising a first strong acid to remove a bulk portion of the high-k dielectric; etching with a second solution comprising water, a second strong acid, an oxidizing agent, and a fluorine compound to remove a second portion of the high-k dielectric; wherein the first solution is not the same as the second solution, the second strong acid is not the same as the fluorine compound, and the second portion of the high-k dielectric is at least {fraction (1/10)}th the thickness of the bulk potion of the high-k dielectric.
Claim 21
Dependent Claim
21 words
The method of claim 18 , wherein the second strong acid is sulfuric acid and the oxidizing agent is hydrogen peroxide.
Claim 22
Dependent Claim
13 words
The method of claim 19 , wherein the fluorine compound is hydrofluoric acid.
Claim 23
Dependent Claim
14 words
The method of claim 20 , wherein the first strong acid is hydrofluoric acid.
Claim 24
Dependent Claim
29 words
The method of claim 18 , wherein etching with the second solution is performed at a temperature of about 60° C. or more and about 140° C. or less.
Claim 25
Independent Claim
59 words
A method of etching through a high-k dielectric layer of at least 1 nm thickness, comprising: providing a high-k dielectric layer of at least 1 nm thickness; wet etching the layer with a solution comprising by volume at least about 25 percent sulfuric acid, at least about 1 percent hydrogen peroxide, and at least about 0.005 percent hydrofluoric acid.
Claim 26
Independent Claim
59 words
A method of etching through a high-k dielectric layer of at least 1 nm thickness, comprising: providing a high-k dielectric layer of at least 1 nm thickness; wet etching the layer with a solution comprising by volume at least about 25 percent sulfuric acid, at least about 1 percent hydrogen peroxide, and at least about 0.005 percent hydrofluoric acid.
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