US5198382A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor element and manufacture thereof
Assignee: STMicroelectronics Ltd Great Britain
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Filing: 1988-04-22
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Granted: 1993-03-30
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Expires: 2008-04-22
Abstract
Abstract A method of fabricating a polycide semiconductor element in which a lift-off mask is formed on a first region of a layer of polysilicon. A first dopant is implanted into second regions of the polysilicon which are adjacent the first region, the first region being masked from implantation by the lift-off mask. A layer of silicide is forced over the implanted regions and the lift-off mask and then the lift-off mask and the respective part of the layer of silicide which is deposited thereover are removed thereby to expose the first region. The method may be used to fabricate a resistive device in a polycide semiconductor element. There is also disclosed a semiconductor element, e.g. a resistive device, made by the method.
Inventors
- 👤 Richard N. Campbell
- 👤 Michael K. Thompson
- 👤 Elizabeth A. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:38
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/40; H10D1/47; H10D1/474; H10B; H10B10/00; H10P; H10P76/00; H10P76/20; H10P76/202; H10B10/15; Y; Y10; Y10S; Y10S257/00; Y10S257/903; Y10S257/904
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
170 words
A method of fabricating a resistive device in polysilicon between two areas of polysilicon in a polycide element, the method comprising the steps of: (a) forming a lift-off mask on a first region of a layer of p-doped polysilicon; (b) implanting an n-dopant into second regions of the polysilicon which are adjacent the first region, such that the second regions have a net excess of n-dopant, the first region being masked from dopant implantation by the lift-off mask; (c) forming a layer of silicide over the implanted regions and the lift-off mask; (d) removing the lift-off mask and the respective layer of silicide formed thereover thereby to leave two portions of silicide interconnect between which the p-doped first region is located; and (e) annealing the silicide at an elevated temperature, the annealing step causing diffusion of the n-dopant from the second regions into respective sides of the first region to form two spaced boundaries between the n- and p-doped regions which are located inwardly of the portions of silicide interconnect.
Claim 2
Independent Claim
170 words
A method of fabricating a resistive device in polysilicon between two areas of polysilicon in a polycide element, the method comprising the steps of: (a) forming a lift-off mask on a first region of a layer of p-doped polysilicon; (b) implanting an n-dopant into second regions of the polysilicon which are adjacent the first region, such that the second regions have a net excess of n-dopant, the first region being masked from dopant implantation by the lift-off mask; (c) forming a layer of silicide over the implanted regions and the lift-off mask; (d) removing the lift-off mask and the respective layer of silicide formed thereover thereby to leave two portions of silicide interconnect between which the p-doped first region is located; and (e) annealing the silicide at an elevated temperature, the annealing step causing diffusion of the n-dopant from the second regions into respective sides of the first region to form two spaced boundaries between the n- and p-doped regions which are located inwardly of the portions of silicide interconnect.
Claim 3
Independent Claim
192 words
A method of fabricating a resistive device in polysilicon between two areas of polysilicon in a polycide element, the method comprising the steps of: (a) forming a lift-off mask on a first region of a layer of polysilicon; (b) implanting an n-dopant into second regions of the polysilicon which are adjacent the first region, such that the second regions have a net excess of n-dopant, the first region being masked from dopant implantation by the lift-off mask; (c) forming a layer of silicide over the implanted regions and the lift-off mask; (d) removing the lift-off mask and the respective layer of silicide formed thereover thereby to leave two portions of silicide interconnect between which the first region is located; and (e) implanting a p-dopant into the first region of layer of polysilicon such that the first region has a net excess of p-dopant; and (f) annealing the silicide at an elevated temperature, the annealing step causing diffusion of the n-dopant from the second regions into respective sides of the first region to form two spaced boundaries between the n- and p-doped regions which are located inwardly of the portions of silicide interconnect.
Claim 4
Independent Claim
192 words
A method of fabricating a resistive device in polysilicon between two areas of polysilicon in a polycide element, the method comprising the steps of: (a) forming a lift-off mask on a first region of a layer of polysilicon; (b) implanting an n-dopant into second regions of the polysilicon which are adjacent the first region, such that the second regions have a net excess of n-dopant, the first region being masked from dopant implantation by the lift-off mask; (c) forming a layer of silicide over the implanted regions and the lift-off mask; (d) removing the lift-off mask and the respective layer of silicide formed thereover thereby to leave two portions of silicide interconnect between which the first region is located; and (e) implanting a p-dopant into the first region of layer of polysilicon such that the first region has a net excess of p-dopant; and (f) annealing the silicide at an elevated temperature, the annealing step causing diffusion of the n-dopant from the second regions into respective sides of the first region to form two spaced boundaries between the n- and p-doped regions which are located inwardly of the portions of silicide interconnect.
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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) | 1996-03-29 | 1996-09-28 | 1997-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-03-29 | 2000-09-28 | 2001-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-03-29 | 2004-09-28 | 2005-03-30 | $7700.00 | Window Closed / Lapsed |