US5913145A
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Method for fabricating thermally stable contacts with a diffusion barrier formed at high temperatures
Assignee: Texas Instruments Inc
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Filing: 1997-08-28
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Granted: 1999-06-15
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Expires: 2017-08-28
Abstract
Abstract In order to provide a thermally stable diffusion barrier for a contact, a layer of titanium is formed on the patterned substrate. A layer of tungsten nitride is formed on the titanium layer. After an annealing step, an interfacial layer and a layer of titanium nitride are formed between the substrate and a tungsten layer. These layers provide a diffusion barrier which is more thermally stable than a titanium nitride layer applied directly on the substrate and permits the formation of a contact structures that can withstand subsequent high temperature steps.
Inventors
- 👤 Jiong-Ping Lu
- 👤 Chih-Chen Cho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:04
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/047; C; C23; C23C; C23C16/00; C23C16/06; C23C16/08; C23C16/16; H10W20/033; Y; Y10; Y10S; Y10S438/00; Y10S438/927
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
54 words
A method of forming a diffusion barrier layer for a contact structure, said method comprising the steps of: forming a layer of titanium on a patterned substrate; forming a layer of tungsten nitride on said titanium layer; annealing said layers along with said substrate to form a titanium nitride layer and a tungsten layer.
Claim 2
Independent Claim
54 words
A method of forming a diffusion barrier layer for a contact structure, said method comprising the steps of: forming a layer of titanium on a patterned substrate; forming a layer of tungsten nitride on said titanium layer; annealing said layers along with said substrate to form a titanium nitride layer and a tungsten layer.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein titanium is replaced by an element selected from the group consisting of cobalt and nickel.
Claim 4
Dependent Claim
36 words
The method of claim 1 wherein said titanium layer is replaced by an MSi x layer or MSi x /M layers, wherein M is a metal selected from the group consisting of titanium, cobalt and nickel.
Claim 5
Dependent Claim
36 words
The method of claim 1 wherein said titanium layer is formed using a CVD process based on the chemical process TiX.sub.4 +H.sub.2 →Ti+HX, where X is selected from the group consisting of chlorine, bromine and iodine.
Claim 6
Dependent Claim
44 words
The method of claim 1 wherein said tungsten nitride layer is formed using CVD process based on a chemical process selected from the group of chemical processes consisting of: WF.sub.6 +NH.sub.3 +H.sub.2 →WN.sub.x +HF, WF.sub.6 +N.sub.2 +H.sub.2 →WN.sub.x +HF, and W(CO).sub.6 +NH.sub.3 →WN.sub.x +CO+H.sub.2.
Claim 7
Dependent Claim
19 words
The method of claim 1 wherein said titanium and/or said tungsten nitride layer are prepared by physical vapor deposition.
Claim 8
Dependent Claim
16 words
The method of claim 1 wherein an additional tungsten layer is added after said annealing step.
Claim 9
Independent Claim
59 words
A method for forming a contract structure, said method comprising the steps of: forming a titanium layer on a substrate; forming a tungsten nitride layer on said titanium layer, forming a tungsten layer on said tungsten nitride layer; and annealing the structure resulting from a formation of these layers to form a titanium nitride layer and a tungsten layer.
Claim 10
Independent Claim
59 words
A method for forming a contract structure, said method comprising the steps of: forming a titanium layer on a substrate; forming a tungsten nitride layer on said titanium layer, forming a tungsten layer on said tungsten nitride layer; and annealing the structure resulting from a formation of these layers to form a titanium nitride layer and a tungsten layer.
Claim 11
Dependent Claim
21 words
The method of claim 8 wherein titanium is replaced by an element selected from the group consisting of cobalt and nickel.
Claim 12
Dependent Claim
37 words
The method of claim 8 wherein said titanium layer is replaced by one of an MSi x layer or a MSi x /M layers, where M is selected from the group consisting of titanium, cobalt, or nickel.
Claim 13
Dependent Claim
39 words
The method of claim 8 wherein said titanium layer is formed using a CVD process based on the chemical process TiX.sub.4 +H.sub.2 →Ti+HX, wherein X is selected from the group consisting of chlorine (Cl), bromine (Br), and iodine (I).
Claim 14
Dependent Claim
45 words
The method of claim 8 wherein said tungsten nitride layer is formed using CVD process based on a chemical process selected from the group of chemical processes consisting of: WF.sub.6 +NH.sub.3 +H.sub.2 →WN.sub.x +HF, WF.sub.6 +N.sub.2 +H.sub.2 →WN.sub.x +HF, and W(CO).sub.6 +NH.sub.3 →WN.sub.x +CO+H.sub.2. 13.
Claim 15
Dependent Claim
19 words
The method of claim 8 wherein said titanium and/or said tungsten nitride layers are prepared by physical vapor deposition.
References Cited (Backward Citations)
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