EP0371854A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for selectively depositing refractory metal on semiconductor substrates
Assignee: MCNC Research and Development Institute
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Filing: 1989-11-22
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Granted: —
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Expires: 2009-11-22
Abstract
Abstract A method for selectively depositing refractory metal (for example tungsten) on the surface (15) of a semiconductor substrate to form an electrical contact, without depositing refractory metal on an adjacent mask layer (11). Refractory metal halide gas and hydrogen gas are simultaneously flowed through a reaction chamber to deposit the refractory metal on the substrate surface and to a lesser extent on the mask layer. Then the flow of hydrogen is interrupted to cause the refractory metal halide to etch the refractory metal which forms on the mask layer. The deposition and etch steps are repeated until the requisite thickness is deposited. The process may take place in a single reaction chamber, using only refractory metal halide gas and pulsed flow of hydrogen gas. A low resistivity refractory metal layer is produced, and damage to the semiconductor surface is minimized.
Inventors
- 👤 Arnold Reisman
- 👤 Gary Wayne Jones
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 03:43
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/40; H10P14/42; H10P14/43; H10P14/432; C; C23; C23C; C23C16/00; C23C16/04; C23C16/06; C23C16/08; C23C16/14; H10P50/00; H10P50/20; H10P50/24; H10P50/242; H10P50/244; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/056; H10W20/057; Y; Y10; Y10S; Y10S148/00; Y10S148/057; Y10S148/058
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
136 words
A method of depositing a predetermined thickness of refractory metal on the surface(15) of a semiconductor substrate (10) having a mask layer (11) thereon and located in a reaction chamber comprising the steps of: flowing refractory metal halide gas and hydrogen gas through said reaction chamber, to thereby react said refractory metal halide gas with said hydrogen gas and deposit refractory metal on said surface (15) and to a lesser extent on said mask layer (11); interrupting the flow of hydrogen gas while continuing the flow of refractory metal halide gas, to thereby cause said refractory metal halide gas to etch said refractory metal on said mask layer and to a lesser extent on said surface; and repeating said flowing and interrupting steps to deposit said predetermined thickness (12) of refractory metal on said surface (15).
Claim 2
Independent Claim
136 words
A method of depositing a predetermined thickness of refractory metal on the surface(15) of a semiconductor substrate (10) having a mask layer (11) thereon and located in a reaction chamber comprising the steps of: flowing refractory metal halide gas and hydrogen gas through said reaction chamber, to thereby react said refractory metal halide gas with said hydrogen gas and deposit refractory metal on said surface (15) and to a lesser extent on said mask layer (11); interrupting the flow of hydrogen gas while continuing the flow of refractory metal halide gas, to thereby cause said refractory metal halide gas to etch said refractory metal on said mask layer and to a lesser extent on said surface; and repeating said flowing and interrupting steps to deposit said predetermined thickness (12) of refractory metal on said surface (15).
Claim 3
Dependent Claim
17 words
The method of Claim 1 wherein said surface is silicon and said mask layer is an insulator.
Claim 4
Dependent Claim
11 words
The method of Claim 2 wherein said insulator is silicon dioxide.
Claim 5
Dependent Claim
11 words
The method of Claim 2 wherein said insulator is silicon nitride.
Claim 6
Dependent Claim
21 words
The method of Claim 1 wherein said refractory metal is tungsten, and wherein said refractory metal halide gas is tungsten hexafluoride.
Claim 7
Dependent Claim
21 words
The method of Claim 1 wherein said refractory metal is molybdenum, and wherein said refractory metal halide gas is molybdenum hexafluoride.
Claim 8
Dependent Claim
25 words
The method of Claim 1 wherein said flowing step is practiced for about 30 seconds and said interrupting step is practiced for about 10 seconds.
Claim 9
Dependent Claim
20 words
The method of Claim 1 wherein the time ratio of said flowing step to said interrupting step is about 3:1.
Claim 10
Dependent Claim
18 words
The method of Claim 1 wherein said flowing and interrupting steps are performed in an argon ambient atmosphere.
Claim 11
Independent Claim
68 words
A method of depositing a refractory metal on the surface of a semiconductor substrate having a mask layer thereon comprising the step of: repeatedly exposing said substrate to refractory metal halide gas and hydrogen gas followed by refractory metal halide gas alone, to thereby etch nucleation sites on said mask layer which are built up during the reaction of said refractory metal halide gas and said hydrogen gas.
Claim 12
Independent Claim
68 words
A method of depositing a refractory metal on the surface of a semiconductor substrate having a mask layer thereon comprising the step of: repeatedly exposing said substrate to refractory metal halide gas and hydrogen gas followed by refractory metal halide gas alone, to thereby etch nucleation sites on said mask layer which are built up during the reaction of said refractory metal halide gas and said hydrogen gas.
Claim 13
Dependent Claim
20 words
The method of Claim 10 wherein said refractory metal is tungsten, and said refractory metal halide gas is tungsten hexafluoride.
Claim 14
Dependent Claim
20 words
The method of Claim 10 wherein said refractory metal is molybdenum, and said refractory metal halide gas is molybdenum hexafluoride.
Claim 15
Dependent Claim
31 words
The method of Claim 10 wherein said substrate is exposed to refractory metal and hydrogen gas for about 30 seconds and to refractory metal halide gas alone for about 10 seconds.
Claim 16
Dependent Claim
34 words
The method of Claim 10 wherein the time ratio of exposing said substrate to refractory metal halide gas and hydrogen gas to exposing said substrate to refractory metal halide gas alone is about 3:1.
Claim 17
Independent Claim
81 words
A method of depositing a refractory metal on the surface of a semiconductor substrate having a mask layer thereon, comprising the step of: providing an ambient atmosphere of refractory metal halide gas and pulses of hydrogen gas to thereby react said hydrogen gas with said refractory metal halide gas and deposit said refractory metal on said surface and to a lesser extent on said mask layer during said pulses, and etch said refractory metal on said mask layer between said pulses.
Claim 18
Independent Claim
81 words
A method of depositing a refractory metal on the surface of a semiconductor substrate having a mask layer thereon, comprising the step of: providing an ambient atmosphere of refractory metal halide gas and pulses of hydrogen gas to thereby react said hydrogen gas with said refractory metal halide gas and deposit said refractory metal on said surface and to a lesser extent on said mask layer during said pulses, and etch said refractory metal on said mask layer between said pulses.
Claim 19
Dependent Claim
21 words
The method of Claim 15 wherein said refractory metal is tungsten, and wherein said refractory metal halide gas is tungsten hexafluoride.
Claim 20
Dependent Claim
21 words
The method of Claim 15 wherein said refractory metal is molybdenum, and wherein said refractory metal halide gas is molybdenum hexafluoride.
Claim 21
Dependent Claim
25 words
The method of Claim 15 wherein said pulses of hydrogen gas have a duration of about 10 seconds, with about 30 seconds between said pulses.
Claim 22
Dependent Claim
23 words
The method of Claim 15 wherein the ratio of the time between said pulses to the duration of said pulses is about 3:1.
References Cited (Backward Citations)
No citation records indexed.
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