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US4816424A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of producing semiconductor device having multilayer conductive lines

Assignee: Fujitsu Ltd
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Filing: 1986-11-10
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Granted: 1989-03-28
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Expires: 2006-11-10
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Abstract

Abstract A triple-layer electrode structure or a multilayer interconnecting structure of a semiconductor device comprising a contact (a lower conductive) layer of aluminum or its alloy which comes into contact with a silicon substrate, a barrier layer of refractory metal nitride (e.g. titanium nitride) and refractory metal (e.g., tungsten), and a (upper) conductive layer of aluminum or its alloy. The TiN-W barrier layer prevents overdissolution of silicon into aluminum in spite of heat-treatment at a relatively elevated temperature. The barrier layer is formed by sintering a mixture of refractory metal nitride powder and refractory metal powder to form a target which is sputter deposited on the contact layer in an atomsphere excluding gaseous nitrogen.

Inventors

  • 👤 Kiyoshi Watanabe
  • 👤 Tohru Takeuchi
  • 👤 Hideaki Ohtake
  • 👤 Ichiro Fujita

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 16:30
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/038; H10D; H10D62/00; H10D62/80; H10D62/83; H10D64/00; H10D64/60; H10D64/62; H10W20/033; H10W20/064; Y; Y10; Y10S; Y10S257/00; Y10S257/915

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 98 words
A method of forming a multilayer structure of a semiconductor device comprising a contact layer in contact with a semiconductor substrate, a barrier layer formed on the contact layer and a conductive layer formed on the barrier layer, comprising the steps of: (a) mixing refractory metal nitride powder and refractory metal powder to produce a refractory metal nitride mixture; (b) sintering the refractory metal nitride mixture to form a target of combined refractory metal nitride; and (c) sputtering the target in an atmosphere substantially excluding nitrogen gas to deposit the combined refractory metal nitride on the contact layer.
Claim 2
Independent Claim 98 words
A method of forming a multilayer structure of a semiconductor device comprising a contact layer in contact with a semiconductor substrate, a barrier layer formed on the contact layer and a conductive layer formed on the barrier layer, comprising the steps of: (a) mixing refractory metal nitride powder and refractory metal powder to produce a refractory metal nitride mixture; (b) sintering the refractory metal nitride mixture to form a target of combined refractory metal nitride; and (c) sputtering the target in an atmosphere substantially excluding nitrogen gas to deposit the combined refractory metal nitride on the contact layer.
Claim 3
Dependent Claim 25 words
The method according to claim 1, wherein said refractory metal is a metal selected from the group consisting of tungsten, titanium, zirconium, hafnium, and tantalum.
Claim 4
Dependent Claim 53 words
A method according to claim 1, further comprising the step of supplying quantities of the refractory metal nitride powder and the refractory metal powder to be mixed in step (a) so that the refractory metal nitride mixture includes the refractory metal nitride powder in a range of 10 to 90 percent by weight.

References Cited (Backward Citations)

US3723838A Cited
US4215156A Cited
FR2402304A1 Cited
US4374912A Cited
JPS57211269A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-03-27 1992-09-26 1993-03-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-03-27 1996-09-26 1997-03-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-03-27 2000-09-26 2001-03-28 $7700.00 Window Closed / Lapsed

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