US5972745A
Expired / Lapsed
US
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Method or forming self-aligned halo-isolated wells
Assignee: International Business Machines Corp
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Filing: 1997-05-30
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Granted: 1999-10-26
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Expires: 2017-05-30
Abstract
Abstract A method of forming a self-aligned halo-isolated well with a single mask is disclosed. First, a layer of resist is disposed over at least a portion of a substrate's surface. Then, an impurity of a first polarity type is implanted at an angle into the substrate through a gap in the layer of resist, thus forming a well having the impurity of the first polarity, which extends beneath the layer of resist. An impurity of a second polarity type is also implanted, using the same mask as previously used. The second implantation forms a well of the impurity of the second polarity disposed within the well of to impurity of the first polarity.
Inventors
- 👤 Howard L. Kalter
- 👤 Edward J. Nowak
- 👤 Xiaowei Tian
- 👤 Minh H. Tong
- 👤 William R. Tonti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:57
CPC Classifications
H; H10; H10D; H10D84/00; H10D84/01; H10D84/0123; H10D84/0126; H10D84/0165; H10D84/0191; H10D84/02; H10D84/03; H10D84/038; H10W; H10W10/00; H10W10/01; H10W10/031; H10W10/30; H10P; H10P30/00; H10P30/20; H10P30/22; H10P30/221; H10P30/222
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
114 words
A method comprising the steps of: a) disposing a layer of resist over at least a portion of a surface of a substrate; b) implanting at an angle into the substrate through a gap in said layer of resist an impurity of a first polarity type, said implanting and said angle sufficient to form a first well of said impurity of the first polarity type extending beneath said layer of resist; and c) implanting an impurity of a second polarity type, using the same mask as used in the step of implanting at an angle, to form a second well of said impurity of the second polarity type disposed entirely within said first well.
Claim 2
Independent Claim
114 words
A method comprising the steps of: a) disposing a layer of resist over at least a portion of a surface of a substrate; b) implanting at an angle into the substrate through a gap in said layer of resist an impurity of a first polarity type, said implanting and said angle sufficient to form a first well of said impurity of the first polarity type extending beneath said layer of resist; and c) implanting an impurity of a second polarity type, using the same mask as used in the step of implanting at an angle, to form a second well of said impurity of the second polarity type disposed entirely within said first well.
Claim 3
Dependent Claim
19 words
The method of claim 1, further comprising the step of: d) forming a transistor entirely within said second well.
Claim 4
Dependent Claim
13 words
The method of claim 1, wherein said substrate comprises said second polarity type.
Claim 5
Dependent Claim
21 words
The method of claim 1, wherein said first polarity type is an n-type and said second polarity type is a p-type.
Claim 6
Dependent Claim
21 words
The method of claim 1, wherein said first polarity type is a p-type and said second polarity type is an n-type.
Claim 7
Dependent Claim
21 words
The method of claim 1, wherein step b) further comprises the step of: rotating said angle to form said first well.
Claim 8
Dependent Claim
30 words
The method of claim 1, further comprising the step of: implanting said first well at an angle within a range of 30 to 60 degrees from normal to the substrate.
Claim 9
Dependent Claim
33 words
The method of claim 1, wherein step c) further comprises the step of: implanting said first well at a energy level greater than an energy level of said implanting of said second well.
Claim 10
Dependent Claim
14 words
The method of claim 1, wherein step b) and step c) are done simultaneously.
Claim 11
Dependent Claim
29 words
The method of claim 6, wherein said implant of said first well is performed at an energy of 20 to 200 Kev and at a dosage of approximately 2E13.
Claim 12
Independent Claim
131 words
A method of forming a MOSFET in a CMOS process comprising the steps of: a) disposing a layer of resist over at least a portion of a surface of a substrate; b) implanting at an angle into the substrate through a gap in said layer of resist an impurity of a first polarity type, said implanting and said angle sufficient to form a first well of said impurity of the first polarity type extending beneath said layer of resist; c) implanting an impurity of a second polarity type, using the same mask as used in the step of implanting at an angle, to form a second well of said impurity of the second polarity type disposed entirely within said first well; and d) forming the MOSFET entirely within said second well.
Claim 13
Independent Claim
131 words
A method of forming a MOSFET in a CMOS process comprising the steps of: a) disposing a layer of resist over at least a portion of a surface of a substrate; b) implanting at an angle into the substrate through a gap in said layer of resist an impurity of a first polarity type, said implanting and said angle sufficient to form a first well of said impurity of the first polarity type extending beneath said layer of resist; c) implanting an impurity of a second polarity type, using the same mask as used in the step of implanting at an angle, to form a second well of said impurity of the second polarity type disposed entirely within said first well; and d) forming the MOSFET entirely within said second well.
Claim 14
Dependent Claim
13 words
The method of claim 11, wherein said substrate comprises said second polarity type.
Claim 15
Dependent Claim
21 words
The method of claim 11, wherein said first polarity type is an n-type and said second polarity type is a p-type.
Claim 16
Dependent Claim
21 words
The method of claim 11, wherein said first polarity type is a p-type and said second polarity type is an n-type.
Claim 17
Dependent Claim
21 words
The method of claim 11, wherein step b) further comprises the step of: rotating said angle to form said first well.
Claim 18
Dependent Claim
30 words
The method of claim 11, further comprising the step of: implanting said first well at an angle within a range of 30 to 60 degrees from normal to the substrate.
Claim 19
Dependent Claim
33 words
The method of claim 11, wherein step c) further comprises the step of: implanting said first well at a energy level greater than an energy level of said implanting of said second well.
Claim 20
Dependent Claim
14 words
The method of claim 11, wherein step b) and step c) are done simultaneously.
Claim 21
Dependent Claim
29 words
The method of claim 17, wherein said implant of said first well is performed at an energy of 20 to 200 Kev and at a dosage of approximately 2E13.
References Cited (Backward Citations)
US3925120A
Cited
US3921283A
Cited
US4907058A
Cited
US4928159A
Cited
US5262345A
Cited
US5770963A
Cited
US5473183A
Cited
US5426063A
Cited
US5578509A
Cited
US5875129A
Cited
US5438542A
Cited
JPH06338617A
Cited
US5500379A
Cited
US5439835A
Cited
US5376566A
Cited
US5409848A
Cited
US5518941A
Cited
US5501993A
Cited
US5534449A
Cited
US5831313A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2002-10-25 | 2003-04-26 | 2003-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-10-25 | 2007-04-26 | 2007-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-10-25 | 2011-04-26 | 2011-10-26 | $7700.00 | Window Closed / Lapsed |