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US5449640A Expired / Lapsed US ⏱️ 0.0 years remaining

Fabricating electrical contacts in semiconductor devices

Assignee: STMicroelectronics Ltd Great Britain
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Filing: 1991-07-19
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Granted: 1995-09-12
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Expires: 2011-07-19
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Abstract

Abstract A method of fabricating an electrical contact in a semiconductor device comprises providing on an underlying silicon substrate a reflowable interlevel dielectric material having a contact opening exposing a contact region of the silicon substrate. The silicon substrate and the interlevel dielectric material are heated by a rapid thermal anneal in an oxygen-containing atmosphere thereby to grow an oxide control layer in the contact region and to reflow the dielectric material. A layer of transition metal is deposited over the reflowed dielectric material and the control layer and at least part of the transition metal layer is converted into a metallurgic barrier.

Inventors

  • 👤 Paul A. Hunt
  • 👤 Ian M. Liles
  • 👤 David R. Guite

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 08:50
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10P; H10P95/00

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 110 words
A method of fabricating an electrical contact in a semiconductor device, the method comprising the steps of: providing on an underlying silicon substrate a reflowable interlevel dielectric material having a contact opening exposing a contact region of the silicon substrate; heating the silicon substrate and the interlevel dielectric material by a rapid thermal anneal in an oxygen-containing atmosphere thereby to grow an oxide control layer in the contact region and to reflow the dielectric material simultaneously, in a single step ; depositing a layer of transition metal over the reflowed dielectric material and the control layer; and converting at least part of the transition metal layer into a metallurgic barrier.
Claim 2
Independent Claim 110 words
A method of fabricating an electrical contact in a semiconductor device, the method comprising the steps of: providing on an underlying silicon substrate a reflowable interlevel dielectric material having a contact opening exposing a contact region of the silicon substrate; heating the silicon substrate and the interlevel dielectric material by a rapid thermal anneal in an oxygen-containing atmosphere thereby to grow an oxide control layer in the contact region and to reflow the dielectric material simultaneously, in a single step ; depositing a layer of transition metal over the reflowed dielectric material and the control layer; and converting at least part of the transition metal layer into a metallurgic barrier.
Claim 3
Dependent Claim 31 words
A method according to claim 1 further comprising the steps of depositing an interconnect layer including aluminium over the metallurgic barrier and depositing a capping metal layer over the interconnect layer.
Claim 4
Dependent Claim 13 words
A method according to claim 2 wherein the capping metal layer comprises titanium.
Claim 5
Dependent Claim 17 words
A method according to claim 1, wherein the reflowable dielectric material comprises a boron phosphorous silicon glass.
Claim 6
Dependent Claim 14 words
A method according to claim 1 wherein the layer of transition metal comprises titanium.
Claim 7
Dependent Claim 23 words
A method according to claim 5 wherein the metallurgic barrier comprises titanium nitride and is formed by nitridation of the layer of titanium.
Claim 8
Independent Claim 117 words
A method of fabricating an electrical contact in a semiconductor device, the method comprising the steps of: providing on an underlying silicon substrate a reflowable interlevel dielectric material having a contact opening exposing a contact region of the silicon substrate; heating the silicon substrate and the interlevel dielectric material by a rapid thermal anneal at a temperature of 950° to 1050° C. in an oxygen-containing atmosphere thereby to grow an oxide control layer in the contact region and to reflow the dielectric material simultaneously, in a single step; depositing a layer of transition metal over the reflowed dielectric material and the control layer; and converting at least part of the transition metal layer into a metallurgic barrier.
Claim 9
Independent Claim 117 words
A method of fabricating an electrical contact in a semiconductor device, the method comprising the steps of: providing on an underlying silicon substrate a reflowable interlevel dielectric material having a contact opening exposing a contact region of the silicon substrate; heating the silicon substrate and the interlevel dielectric material by a rapid thermal anneal at a temperature of 950° to 1050° C. in an oxygen-containing atmosphere thereby to grow an oxide control layer in the contact region and to reflow the dielectric material simultaneously, in a single step; depositing a layer of transition metal over the reflowed dielectric material and the control layer; and converting at least part of the transition metal layer into a metallurgic barrier.
Claim 10
Dependent Claim 31 words
A method according to claim 7 further comprising the steps of depositing an interconnect layer including aluminum over the metallurgic barrier and depositing a capping metal layer over the interconnect layer.
Claim 11
Dependent Claim 13 words
A method according to claim 8 wherein the capping metal layer comprises titanium.-
Claim 12
Dependent Claim 17 words
A method according to claim 7 wherein the reflowable dielectric material comprises a boron phosphorus silicon glass.
Claim 13
Dependent Claim 14 words
A method according to claim 7 wherein the layer of transition metal comprises titanium.
Claim 14
Dependent Claim 23 words
A method according to claim 11 wherein the metallurgic barrier comprises titanium nitride and is formed by nitridation of the layer of titanium.

References Cited (Backward Citations)

DE2825433A1 Cited
US4271424A Cited
EP0186296A2 Cited
JPS6222437A Cited
EP0273629A2 Cited
US4784973A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-09-11 1999-03-13 1999-09-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-09-11 2003-03-13 2003-09-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-09-11 2007-03-13 2007-09-12 $7700.00 Window Closed / Lapsed

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