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US5202287A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for a two step selective deposition of refractory metals utilizing SiH4 reduction and H2 reduction

Assignee: GlobalFoundries Inc
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Filing: 1992-01-06
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Granted: 1993-04-13
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Expires: 2012-01-06
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Abstract

Abstract Selective deposition of a refractory metal on a silicon substrate utilizing high temperatures and a silane reduction process in which the flow rate ratio of silane to refractory metal halide gas is less than one. In a second embodiment, an additional layer of the refractory metal is deposited utilizing a hydrogen reduction of the metal halide gas at very high temperatures. In both embodiments, a refractory metal barrier layer may be provided by forming a self-aligned refractory metal silicide layer. Alternatively, a two layer self-aligned barrier is formed of a refractory metal silicide lower layer and a refractory metal nitride upper layer and the refractory metal is selectively deposited on the metal nitride.

Inventors

  • 👤 Rajiv V. Joshi
  • 👤 Choon-Sik Oh
  • 👤 Dan Moy

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 09:53
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/069; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0112; H10P; H10P14/00; H10P14/40; H10P14/42; H10P14/43; H10P14/432; H10W20/032; Y; Y10; Y10S; Y10S148/00; Y10S148/025

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 107 words
A method for selectively depositing a refractory metal on exposed surfaces of a silicon substrate having oxide regions thereon and located in a deposition apparatus, the method comprising the steps of: (a) introducing a mixture of silane gas and a refractory metal halide gas into said deposition apparatus such that said gases react to selectively deposit a first refractory metal layer on said exposed silicon surfaces; and (b) stopping the introduction of silane and introducing hydrogen with said refractory metal hexahalide gas in said deposition apparatus such that said hydrogen reacts with said refracting metal hexahalide to further selectively deposit refractory metal on said exposed silicon surfaces.
Claim 2
Independent Claim 107 words
A method for selectively depositing a refractory metal on exposed surfaces of a silicon substrate having oxide regions thereon and located in a deposition apparatus, the method comprising the steps of: (a) introducing a mixture of silane gas and a refractory metal halide gas into said deposition apparatus such that said gases react to selectively deposit a first refractory metal layer on said exposed silicon surfaces; and (b) stopping the introduction of silane and introducing hydrogen with said refractory metal hexahalide gas in said deposition apparatus such that said hydrogen reacts with said refracting metal hexahalide to further selectively deposit refractory metal on said exposed silicon surfaces.
Claim 3
Dependent Claim 35 words
The method of claim 1 said silane and refractory metal halide gases are introduced at a ratio of the flow rates of the silane with respect to the refractory metal hexafluoride of less than 1.
Claim 4
Dependent Claim 28 words
The method of claim 2 wherein the depositing of the first refractory metal layer is performed at a deposition temperature in the range of 370° to 550° C.
Claim 5
Dependent Claim 21 words
The method of claim 3 wherein the further selective deposition of refractory metal is at a deposition temperature above 500° C.
Claim 6
Dependent Claim 23 words
The method of claim 1 wherein the refractory metal halide gas is a refractory metal pentahalide gas or a refractory metal hexahalide gas.
Claim 7
Dependent Claim 25 words
The method of claim 1 or 5 wherein the refractory metal halide gas is a refractory metal chloride gas or a refractory metal fluoride gas.
Claim 8
Dependent Claim 24 words
The method of claim 1 wherein the refractory metal layer comprises a refractory metal selected from the group consisting of tungsten, molybdenum and tantalum.
Claim 9
Dependent Claim 30 words
The method of claim 7 further including the step of depositing a refractory metal barrier layer on said exposed silicon surface prior to the deposition of said refractory metal layer.
Claim 10
Dependent Claim 14 words
The method of claim 7 wherein said barrier layer comprises a refractory metal silicide.
Claim 11
Dependent Claim 23 words
The method of claim 8 wherein said barrier layer comprises a refractory metal silicide lower layer and a refractory metal nitride upper layer.
Claim 12
Dependent Claim 34 words
The method of claim 10 wherein said barrier layer is formed by depositing a self-aligned refractory metal silicide layer and subsequently converting the surface of said silicide layer to a refractory metal nitride layer.
Claim 13
Dependent Claim 55 words
The method of claim 11 wherein said self-aligned refractory metal silicide layer is deposited by depositing a blanket layer of a refractory metal on said substrate, annealing said substrate to convert the refractory metal disposed on said exposed silicon surfaces to a refractory metal silicide, and etching away the unconverted portions of said refractory metal.
Claim 14
Independent Claim 37 words
The method of claims 8, 9, 10, 11 or 12 wherein said refractory metal barrier layer comprises a silicide and/or nitride of a refractory metal selected from the group consisting of titantium, niobium, zirconium, chromium and hafnium.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-04-12 1996-10-12 1997-04-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-04-12 2000-10-12 2001-04-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-04-12 2004-10-12 2005-04-13 $7700.00 Window Closed / Lapsed

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