US6200864B1
Expired / Lapsed
US
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Method of asymmetrically doping a region beneath a gate
Assignee: Advanced Micro Devices Inc
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Filing: 1999-06-23
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Granted: 2001-03-13
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Expires: 2019-06-23
Abstract
Abstract A method of asymmetrically doping a region beneath a gate by controlling the lateral surface profile of the gate using a mask. A first embodiment of the method includes forming a mask over the gate such that it extends beyond the opposing sides of the gate in an uneven manner. A second embodiment of the method includes forming a mask including sidewall spacers on both sides of the gate in an uneven manner. The uneven manner of providing the mask for ion implantation can be used to define an asymmetric lateral channel profile, which can be advantageously used to vary gate overlap, channel V T , or source/drain doping as necessary.
Inventors
- 👤 Asim Selcuk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:31
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/015; H10D30/00; H10D30/01; H10D30/021; H10D30/0221; H10D30/0223; H10D30/60; H10D30/637; H10D64/021; H10P; H10P30/00; H10P30/20; H10P30/22
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
122 words
A method of asymmetrically doping a channel region beneath a gate on a substrate comprising the steps of: forming a first pair of sidewall spacers on opposing sides of the gate; forming a second pair of sidewall spacers on the first pair of sidewall spacers on opposing sides of the gate; removing one of the second sidewall spacers from one side of the gate; and implanting dopants in the substrate using the remaining sidewalls spacers as a mask to form two overlapping well regions in the substrate extending beneath the gate and within the channel region, wherein the channel region beneath the gate having one sidewall spacer contains more dopant than the channel region beneath the gate having two side wall spacers.
Claim 2
Independent Claim
122 words
A method of asymmetrically doping a channel region beneath a gate on a substrate comprising the steps of: forming a first pair of sidewall spacers on opposing sides of the gate; forming a second pair of sidewall spacers on the first pair of sidewall spacers on opposing sides of the gate; removing one of the second sidewall spacers from one side of the gate; and implanting dopants in the substrate using the remaining sidewalls spacers as a mask to form two overlapping well regions in the substrate extending beneath the gate and within the channel region, wherein the channel region beneath the gate having one sidewall spacer contains more dopant than the channel region beneath the gate having two side wall spacers.
Claim 3
Dependent Claim
46 words
The method according to claim 1 , wherein the step of forming a first pair of sidewall spacers comprises the steps of: depositing a layer of nitride upon the gate and substrate; and anisotropically etching the nitride layer to form the first pair of sidewall spacers.
Claim 4
Dependent Claim
49 words
The method according to claim 2 , wherein the step of forming a second pair of sidewall spacers comprises the steps of: depositing a layer of oxide upon the substrate, gate, and the nitride spacers; and anisotropically etching the oxide layer to form the second pair of sidewall spacers.
Claim 5
Dependent Claim
52 words
The method according to claim 3 , wherein the step of removing one of the second sidewall spacers comprises the steps of: positioning a mask to cover the spacers on one side of the gate while exposing the spacers on the opposing side of the gate; and etching the exposed oxide spacer.
Claim 6
Dependent Claim
16 words
The method according to claim 4 , further comprising removing the mask covering the sidewall spacers.
Claim 7
Dependent Claim
46 words
The method according to claim 1 , wherein the step of forming a first pair of sidewall spacers comprise the steps of: depositing a layer of oxide upon the gate and substrate; and anisotropically etching the oxide layer to form the first pair of sidewall spacers.
Claim 8
Dependent Claim
48 words
The method according to claim 6 , wherein the step of forming the second pair of sidewall spacers comprises the steps of: depositing a layer of nitride upon the substrate, gate, and oxide spacers; and anisotropically etching the nitride layer to form the second pair of sidewall spacers.
Claim 9
Dependent Claim
52 words
The method according to claim 7 , wherein the step of removing one of the second sidewall spacers comprises the steps of: positioning a mask to cover the spacers on one side of the gate while exposing the spacers on the opposing side of the gate; and etching the exposed nitride spacers.
Claim 10
Dependent Claim
16 words
The method according to claim 8 , further comprising removing the mask covering the sidewall spacers.
Claim 11
Independent Claim
124 words
A method of asymmetrically doping channel region beneath a gate on a substrate comprising the steps of: forming a first pair of sidewall spacers on opposing sides of the gate; removing one of the first sidewall spacers from one side of the gate; forming a second pair of sidewall spacers on opposing sides of the gate and the remaining first sidewall spacer; and implanting dopants in the substrate using the remaining first sidewall spacer and second sidewall spacers as a mask to form two overlapping well regions in the substrate extending beneath the gate and within the channel region, wherein the channel region beneath the gate having one sidewall spacer contains more dopant than the channel region beneath the gate having two sidewall spacers.
Claim 12
Independent Claim
124 words
A method of asymmetrically doping channel region beneath a gate on a substrate comprising the steps of: forming a first pair of sidewall spacers on opposing sides of the gate; removing one of the first sidewall spacers from one side of the gate; forming a second pair of sidewall spacers on opposing sides of the gate and the remaining first sidewall spacer; and implanting dopants in the substrate using the remaining first sidewall spacer and second sidewall spacers as a mask to form two overlapping well regions in the substrate extending beneath the gate and within the channel region, wherein the channel region beneath the gate having one sidewall spacer contains more dopant than the channel region beneath the gate having two sidewall spacers.
Claim 13
Dependent Claim
46 words
The method according to claim 10 , wherein the step of forming a first pair of sidewall spacers comprises the steps of: depositing a layer of nitride upon the gate and substrate; and anisotropically etching the nitride layer to form the first pair of sidewall spacers.
Claim 14
Dependent Claim
49 words
The method according to claim 11 , wherein the step of removing one of the first sidewall spacers comprises the steps of: positioning a mask to cover one of the nitride spacers while exposing the spacer on the opposing side of the gate; and etching the exposed nitride spacer.
Claim 15
Dependent Claim
16 words
The method according to claim 12 , further comprising removing the mask covering the nitride spacer.
Claim 16
Dependent Claim
51 words
The method according to claim 13 , wherein the step of forming a second pair of sidewall spacers comprises the steps of: depositing a layer of oxide upon the substrate, gate, and the remaining nitride sidewall spacer; and anisotropically etching the oxide layer to form the second pair of sidewall spacers.
Claim 17
Dependent Claim
46 words
The method according to claim 10 , wherein the step of forming a first pair of sidewall spacers comprises the steps of: depositing a layer of oxide upon the gate and substrate; and anisotropically etching the oxide layer to form the first pair of sidewall spacers.
Claim 18
Dependent Claim
49 words
The method according to claim 15 , wherein the step of removing one of the first sidewall spacers comprises the steps of: positioning a mask to cover one of the oxide spacers while exposing the spacer on the opposing side of the gate; and etching the exposed oxide spacer.
Claim 19
Dependent Claim
16 words
The method according to claim 16 , further comprising removing the mask covering the oxide spacer.
Claim 20
Dependent Claim
50 words
The method according to claim 17 , wherein the step of forming a second pair of sidewall spacers comprises the steps of: depositing a layer of nitride upon the gate and the remaining oxide sidewall spacer; and anisotropically etching the nitride layer to form the second pair of sidewall spacers.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-03-12 | 2004-09-11 | 2005-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-12 | 2008-09-11 | 2009-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-12 | 2012-09-11 | 2013-03-13 | $7700.00 | Window Closed / Lapsed |