US5602055A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing a semiconductor device incorporating a selectively deposited contact
Assignee: STMicroelectronics Ltd Great Britain
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Filing: 1995-06-07
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Granted: 1997-02-11
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Expires: 2015-06-07
Abstract
Abstract A semiconductor device comprising a silicon substrate, an oxide layer on the silicon substrate, a doped polysilicon region disposed on the oxide layer, a dielectric layer which has been deposited over the doped polysilicon region and the silicon substrate, a contact hole which is formed in the dielectric layer and extends over respective laterally adjacent portions of the doped polysilicon region and the silicon substrate and a contact which has been selectively deposited in the contact hole which electrically connects the said portions together. The invention also provides a method of fabricating a semiconductor device incorporating a refractory metal contact, the method comprising the steps of:--a) providing a semiconductor substrate having an oxide layer thereon and a doped polysilicon region disposed on the oxide layer; (b) depositing a dielectric layer over the doped polysilicon region and over the silicon substrate; (c) forming a contact hole in the dielectric layer which exposes a portion of the doped polysilicon region and a laterally adjacent portion of the silicon substrate; and (d) selectively depositing a contact into the contact hole thereby electrically to connect together the doped polysilicon region and the silicon substrate.
Inventors
- 👤 Howard C. Nicholls
- 👤 Michael J. Norrington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:51
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/056; H10W20/069; H10W20/0698; H10W20/40; Y; Y10; Y10S; Y10S257/00; Y10S257/90
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
136 words
A method of fabricating a semiconductor device incorporating a refractory metal contact, the method comprising the steps of: (a) providing a silicon substrate having an oxide layer thereon, a doped polysilicon region disposed on the oxide layer and a silicon nitride layer over the doped polysilicon region and the oxide layer; (b) forming side wall spacers on the silicon nitride layer adjacent the doped polysilicon region; (c) depositing a dielectric layer over the side wall spacers and the silicon nitride layer; (d) forming a contact hole in the dielectric layer which removes one side wall spacer and exposes a portion of the doped polysilicon region and a laterally adjacent portion of the silicon substrate; and (e) selectively depositing a contact into the contact hole thereby electrically connecting together the doped polysilicon region and the silicon substrate.
Claim 2
Independent Claim
136 words
A method of fabricating a semiconductor device incorporating a refractory metal contact, the method comprising the steps of: (a) providing a silicon substrate having an oxide layer thereon, a doped polysilicon region disposed on the oxide layer and a silicon nitride layer over the doped polysilicon region and the oxide layer; (b) forming side wall spacers on the silicon nitride layer adjacent the doped polysilicon region; (c) depositing a dielectric layer over the side wall spacers and the silicon nitride layer; (d) forming a contact hole in the dielectric layer which removes one side wall spacer and exposes a portion of the doped polysilicon region and a laterally adjacent portion of the silicon substrate; and (e) selectively depositing a contact into the contact hole thereby electrically connecting together the doped polysilicon region and the silicon substrate.
Claim 3
Dependent Claim
41 words
A method according to claim 1 further comprising the step, after step (e) of depositing a metal capping layer over the contact which covers the upper surface of the contact and adjacent portions of the upper surface of the dielectric layer.
Claim 4
Dependent Claim
38 words
A method according to claim 1 further comprising the step of implanting dopant into regions of the silicon substrate which are not masked by the doped polysilicon region and the side wall spacers thereby to form implanted regions.
Claim 5
Dependent Claim
46 words
A method according to claim 3 further comprising the step, before or after the step of forming the side wall spacers, of implanting dopant into the silicon substrate thereby to form doped regions in the silicon substrate which are lightly doped relative to the implanted regions.
Claim 6
Dependent Claim
28 words
A method according to claim 1 further comprising the step of forming a second silicon nitride layer over the side wall spacers and the first-mentioned silicon nitride layer.
Claim 7
Dependent Claim
25 words
A method according to claim 1 wherein the doped polysilicon region and the portion of the silicon substrate are doped with dopants of opposite polarity.
Claim 8
Dependent Claim
22 words
A method according to claim 1 wherein the contact hole is formed in a single etch step in which silicon is unetched.
Claim 9
Independent Claim
121 words
A method of fabricating a semiconductor device incorporating a refractory metal contact, the method comprising the steps of: (a) providing a silicon substrate having an oxide layer thereon and a doped polysilicon region disposed on the oxide layer; (b) forming side wall spacers adjacent the doped polysilicon region; (c) depositing a dielectric layer over the doped polysilicon region, the side wall spacers and the silicon substrate; (d) forming a contact hole in the dielectric layer which removes one side wall spacer and exposes a portion of the doped polysilicon region and a laterally adjacent portion of the silicon substrate; and (e) selectively depositing a contact into the contact hole thereby electrically connecting together the doped polysilicon region and the silicon substrate.
Claim 10
Independent Claim
121 words
A method of fabricating a semiconductor device incorporating a refractory metal contact, the method comprising the steps of: (a) providing a silicon substrate having an oxide layer thereon and a doped polysilicon region disposed on the oxide layer; (b) forming side wall spacers adjacent the doped polysilicon region; (c) depositing a dielectric layer over the doped polysilicon region, the side wall spacers and the silicon substrate; (d) forming a contact hole in the dielectric layer which removes one side wall spacer and exposes a portion of the doped polysilicon region and a laterally adjacent portion of the silicon substrate; and (e) selectively depositing a contact into the contact hole thereby electrically connecting together the doped polysilicon region and the silicon substrate.
Claim 11
Dependent Claim
41 words
A method according to claim 8 further comprising the step, after step (e), of depositing a metal capping layer over the contact which covers the upper surface of the contact and adjacent portions of the upper surface of the dielectric layer.
Claim 12
Dependent Claim
41 words
A method according to claim 8 further comprising the step, before step (b), of depositing a silicon nitride layer over the doped polysilicon region and the oxide layer and wherein the side wall spacers are deposited on the silicon nitride layer.
Claim 13
Dependent Claim
38 words
A method according to claim 8 further comprising the step of implanting dopant into regions of the silicon substrate which are not masked by the doped polysilicon region and the side wall spacers thereby to form implanted regions.
Claim 14
Dependent Claim
46 words
A method according to claim 11 further comprising the step, before or after the step of forming the side wall spacers, of implanting dopant into the silicon substrate thereby to form doped regions in the silicon substrate which are lightly doped relative to the implanted regions.
Claim 15
Dependent Claim
28 words
A method according to claim 10 further comprising the step of forming a second silicon nitride layer over the side wall spacers and the first-mentioned silicon nitride layer.
Claim 16
Dependent Claim
25 words
A method according to claim 8 wherein the doped polysilicon region and the portion of the silicon substrate are doped with dopants of opposite polarity.
Claim 17
Dependent Claim
22 words
A method according to claim 8 wherein the contact hole is formed in a single etch step in which silicon is unetched.
Claim 18
Dependent Claim
29 words
A method according to claim 8 further comprising the step of forming a silicon nitride layer over the side wall spacers, the doped polysilicon region and the oxide layer.
Claim 19
Independent Claim
180 words
A method of fabricating a semiconductor device incorporating a tungsten metal contact, the method comprising the steps of: (a) providing a silicon substrate having an oxide layer thereon, a doped polysilicon region disposed on the oxide layer and a further layer over the doped polysilicon region and the oxide layer; (b) forming side wall spacers on the further layer adjacent the doped polysilicon region by depositing a first dielectric layer over the further layer and etching the first dielectric layer to form the side wall spacers, the further layer acting as an etch stop layer during the etch; (c) depositing a second dielectric layer over the side wall spacers and the further layer; (d) etching a contact hole in the second dielectric layer which removes one side wall spacer and exposes a portion of the doped polysilicon region and a laterally adjacent portion of the silicon substrate; and (e) selectively depositing a tungsten contact into the contact hole thereby electrically connecting together the doped polysilicon region and the silicon substrate, the contact abutting a side of the doped polysilicon region.
Claim 20
Independent Claim
180 words
A method of fabricating a semiconductor device incorporating a tungsten metal contact, the method comprising the steps of: (a) providing a silicon substrate having an oxide layer thereon, a doped polysilicon region disposed on the oxide layer and a further layer over the doped polysilicon region and the oxide layer; (b) forming side wall spacers on the further layer adjacent the doped polysilicon region by depositing a first dielectric layer over the further layer and etching the first dielectric layer to form the side wall spacers, the further layer acting as an etch stop layer during the etch; (c) depositing a second dielectric layer over the side wall spacers and the further layer; (d) etching a contact hole in the second dielectric layer which removes one side wall spacer and exposes a portion of the doped polysilicon region and a laterally adjacent portion of the silicon substrate; and (e) selectively depositing a tungsten contact into the contact hole thereby electrically connecting together the doped polysilicon region and the silicon substrate, the contact abutting a side of the doped polysilicon region.
Claim 21
Dependent Claim
38 words
A method according to claim 17 further comprising the step of implanting dopant into regions of the silicon substrate which are not masked by the doped polysilicon region and the side wall spacers thereby to form implanted regions.
Claim 22
Dependent Claim
46 words
A method according to claim 18 further comprising the step, before or after the step of forming the side wall spacers, of implanting dopant into the silicon substrate thereby to form doped regions in the silicon substrate which are lightly doped relative to the implanted regions.
Claim 23
Dependent Claim
24 words
A method according to claim 17 further comprising the step of forming a sealing layer over the side wall spacers and the further layer.
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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) | 2000-02-11 | 2000-08-12 | 2001-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-02-11 | 2004-08-12 | 2005-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-02-11 | 2008-08-12 | 2009-02-11 | $7700.00 | Window Closed / Lapsed |