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US5861340A
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Method of forming a polycide film
Assignee: Intel Corp
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Filing: 1996-02-15
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Granted: 1999-01-19
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Expires: 2016-02-15
Abstract
Abstract A method of forming a polycide thin film. First, a silicon layer is formed. Next, a thin barrier layer is formed on the first silicon layer. A second silicon layer is then formed on the barrier layer. Next, a metal layer is formed on the second silicon layer. The metal layer and the second silicon layer are then reacted together to form a silicide.
Inventors
- 👤 Gang Bai
- 👤 David B. Fraser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:03
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/01; H10D30/021; H10D30/0223; H10D30/0227; H10D30/0212; H10D64/00; H10D64/01; H10D64/013; H10D64/01302; H10D64/01304; H10D64/01306; H10D64/01308; H10D64/0131; H10D64/60; H10D64/66; H10D64/661; H10D64/662; H10D64/664
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
72 words
A method of forming a polycide film, said method comprising the steps of: forming a first silicon layer; forming a barrier layer on said first silicon layer; forming a second silicon layer on said barrier layer; forming a metal layer on said second silicon layer; forming a silicide layer by reacting said metal layer and said second silicon layer; and diffusing a dopant through said barrier layer to said first silicon layer.
Claim 2
Independent Claim
72 words
A method of forming a polycide film, said method comprising the steps of: forming a first silicon layer; forming a barrier layer on said first silicon layer; forming a second silicon layer on said barrier layer; forming a metal layer on said second silicon layer; forming a silicide layer by reacting said metal layer and said second silicon layer; and diffusing a dopant through said barrier layer to said first silicon layer.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein said barrier layer is silicon dioxide.
Claim 4
Dependent Claim
17 words
The method of claim 2 wherein said barrier layer is formed to a thickness between 5-25 Å.
Claim 5
Dependent Claim
18 words
The method of claim 1 wherein said first silicon layer and said second silicon layer are polycrystalline silicon.
Claim 6
Dependent Claim
18 words
The method of claim 1 wherein said first silicon layer and said second silicon layer are amorphous silicon.
Claim 7
Dependent Claim
34 words
The method of claim 1 wherein said barrier layer is formed to a thickness sufficient to prevent silicon from said first polysilicon layer from diffusing through said barrier layer during said silicide formation step.
Claim 8
Dependent Claim
22 words
The method of claim 1 wherein said metal layer is selected from the group consisting of: titanium, cobalt, palladium, nickel, and platinum.
Claim 9
Dependent Claim
17 words
The method of claim 1 wherein said step of forming said silicide utilizes a Rapid Thermal Process.
Claim 10
Dependent Claim
18 words
The method of claim 1 wherein said second silicon layer is substantially consumed during said silicide formation step.
Claim 11
Dependent Claim
32 words
The method of claim 1 wherein said metal layer is selected from the group consisting of titanium and cobalt, and wherein said silicide is formed at a temperature greater than 800° C.
Claim 12
Dependent Claim
32 words
The method of claim 1 wherein said metal layer is selected from the group consisting of palladium, nickel, and platinum, and said silicide is formed at a temperature greater than 700° C.
Claim 13
Independent Claim
119 words
A method of forming a polycide gate electrode on a semiconductor substrate, said method comprising the steps of: depositing a first polysilicon layer on a gate dielectric layer formed on a semiconductor substrate; forming a 5-25 Å thick silicon dioxide layer on said first polysilicon layer; depositing a second polysilicon layer on said thin oxide layer; patterning said second polysilicon layer, said thin oxide layer, and said first polysilicon layer into a gate electrode; forming spacers adjacent to the outside edges of said gate electrode; depositing a metal layer over said substrate, said spacers, and said second polysilicon layer; and annealing said substrate so that said metal layer and said second polysilicon layer form a low resistance silicide layer.
Claim 14
Independent Claim
119 words
A method of forming a polycide gate electrode on a semiconductor substrate, said method comprising the steps of: depositing a first polysilicon layer on a gate dielectric layer formed on a semiconductor substrate; forming a 5-25 Å thick silicon dioxide layer on said first polysilicon layer; depositing a second polysilicon layer on said thin oxide layer; patterning said second polysilicon layer, said thin oxide layer, and said first polysilicon layer into a gate electrode; forming spacers adjacent to the outside edges of said gate electrode; depositing a metal layer over said substrate, said spacers, and said second polysilicon layer; and annealing said substrate so that said metal layer and said second polysilicon layer form a low resistance silicide layer.
Claim 15
Dependent Claim
45 words
The method of claim 12 further comprising the step of: after forming said spacers, ion implanting impurities into said semiconductor substrate in alignment with the outside edges of said spacers, and into said gate electrode to form source/drain regions and to dope said gate electrode.
Claim 16
Dependent Claim
19 words
The method of claim 12 wherein said thin silicon dioxide layer is formed to a thickness between 10-20 Å.
Claim 17
Dependent Claim
37 words
The method of claim 12 wherein said thin silicon dioxide layer is formed to a thickness sufficient to prevent silicon atoms from said first polysilicon layer from diffusing through said thin oxide layer during said annealing step.
Claim 18
Dependent Claim
22 words
The method of claim 12 wherein said metal layer is selected from the group consisting of titanium, cobalt, palladium, nickel, and platinum.
Claim 19
Dependent Claim
31 words
The method of claim 12 wherein said second polysilicon layer and said metal layer are formed to thicknesses so that they are both substantially consumed into silicide during said annealing step.
Claim 20
Dependent Claim
23 words
The method of claim 12 wherein said thin silicon dioxide layer is formed by exposing said first polysilicon layer to an air ambient.
Claim 21
Dependent Claim
13 words
The method of claim 12 wherein said anneal comprises a Rapid Thermal Anneal.
Claim 22
Dependent Claim
21 words
The method of claim 12 wherein said gate electrode has a gate length of less than or equal to 0.25 microns.
Claim 23
Dependent Claim
24 words
The method of claim 12 wherein said first polysilicon layer is between 500-3000 Å thick and said silicide layer is approximately 500 Å thick.
Claim 24
Dependent Claim
19 words
The method of claim 12 wherein said first polysilicon layer is approximately four times thicker than said silicide layer.
Claim 25
Independent Claim
83 words
A method of forming a polycide film, said method comprising the steps of: forming a first silicon layer; forming a passivating barrier layer having a thickness between 5-25 Å on said first silicon layer; forming a second silicon layer on said passivating barrier layer; forming a metal layer on said second silicon layer; forming a silicide layer by reacting said metal layer and said second silicon layer, wherein said passivating barrier layer resists reaction of said metal layer with said first silicon layer.
Claim 26
Independent Claim
83 words
A method of forming a polycide film, said method comprising the steps of: forming a first silicon layer; forming a passivating barrier layer having a thickness between 5-25 Å on said first silicon layer; forming a second silicon layer on said passivating barrier layer; forming a metal layer on said second silicon layer; forming a silicide layer by reacting said metal layer and said second silicon layer, wherein said passivating barrier layer resists reaction of said metal layer with said first silicon layer.
Claim 27
Independent Claim
77 words
A method of forming a polycide film, said method comprising the steps of: forming a first silicon layer; forming a barrier layer on said first silicon layer; forming a second silicon layer on said barrier layer; and forming a silicide layer by reacting said metal layer and said second silicon layer, wherein said barrier layer has a thickness of between 5-25 Å and is selected from the group consisting of silicon dioxide, silicon oxynitride, and silicon nitride.
Claim 28
Independent Claim
77 words
A method of forming a polycide film, said method comprising the steps of: forming a first silicon layer; forming a barrier layer on said first silicon layer; forming a second silicon layer on said barrier layer; and forming a silicide layer by reacting said metal layer and said second silicon layer, wherein said barrier layer has a thickness of between 5-25 Å and is selected from the group consisting of silicon dioxide, silicon oxynitride, and silicon nitride.
References Cited (Backward Citations)
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