US6599644B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making an ohmic contact to p-type silicon carbide, comprising titanium carbide and nickel silicide
Assignee: Foundation for Research and Technology-Hellas
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Filing: 2001-10-04
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Granted: 2003-07-29
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Expires: 2021-10-04
Abstract
Abstract A method of producing an ohmic contact to p-type silicon carbide comprising two layers, the first one comprising nickel silicide and the second one comprising titanium carbide is disclosed. The deposited layers are annealed to convert at least a part of deposited metals to nickel silicide and titanium carbide. The contact is formed by reaction between the metals and the semiconductor, and thus the in-situ simultaneous formation of metal silicide and carbide suppress the release of excess carbon at the contact interface. Noble metals may be deposited preferably in between titanium and nickel to improve the contact morphology.
Inventors
- 👤 Konstantinos Zekentes
- 👤 Konstantin V. Vassilievski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:56
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0115; H10D62/00; H10D62/80; H10D62/83; H10D62/832; H10D62/8325; H10D64/60; H10D64/62; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12535; Y10T428/12576; Y10T428/12583; Y10T428/12736; Y10T428/12743; Y10T428/12771; Y10T428/12861; Y10T428/12931
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
103 words
A method of forming an ohmic contact to a p-type SiC substrate, comprising the steps of: (A)(1) depositing a layer of aluminum, titanium and nickel, in that order, on said p-type SiC substrate to form aluminum, titanium and nickel metal contacts; (2) optionally repeating said step (A)(1) one or more times to form a series of said aluminum, titanium and nickel layers; and then, (B) heat treating the resulting article for sufficient time and at sufficient temperature to convert at least part of said deposited material to titanium carbide and nickel silicide by reaction of SiC with said titanium and nickel metal contacts.
Claim 2
Independent Claim
103 words
A method of forming an ohmic contact to a p-type SiC substrate, comprising the steps of: (A)(1) depositing a layer of aluminum, titanium and nickel, in that order, on said p-type SiC substrate to form aluminum, titanium and nickel metal contacts; (2) optionally repeating said step (A)(1) one or more times to form a series of said aluminum, titanium and nickel layers; and then, (B) heat treating the resulting article for sufficient time and at sufficient temperature to convert at least part of said deposited material to titanium carbide and nickel silicide by reaction of SiC with said titanium and nickel metal contacts.
Claim 3
Dependent Claim
28 words
The method of claim 1 , wherein said heat treatment is carried out at a temperature in the range of from about 850° C. to about 1150° C.
Claim 4
Dependent Claim
24 words
The method of claim 1 , wherein one or more layers of noble metals are deposited in between said titanium and nickel metal contacts.
Claim 5
Dependent Claim
16 words
The method of claim 3 , wherein said noble metals are platinum, gold or palladium species.
Claim 6
Dependent Claim
36 words
The method of claim 1 or 3 wherein at least one of said depositing layers is formed using a method selected from the group consisting of chemical vapor deposition, sputtering and evaporation from a metal source.
Claim 7
Dependent Claim
23 words
The method of claim 1 , wherein said p-type SiC substrate is a part of multilayer epitaxial structure or single crystal of SiC.
Claim 8
Dependent Claim
22 words
The method of claim 1 , wherein said p-type SiC substrate has an acceptor concentration of 10 18 cm −3 or higher.
Claim 9
Dependent Claim
24 words
The method of claim 1 , wherein said contact has a specific contact resistance to SiC of less than 10 −4 ohm·cm 2 .
Claim 10
Dependent Claim
42 words
An ohmic contact to a p-type SiC substrate, said ohmic contact comprising a layer of aluminum, titanium and nickel, deposited in that order on said p-type SiC substrate, wherein aluminum, titanium and nickel of said layer form titanium carbide and nickel silicide.
Claim 11
Dependent Claim
42 words
An ohmic contact to a p-type SiC substrate, said ohmic contact comprising a layer of aluminum, titanium and nickel, deposited in that order on said p-type SiC substrate, wherein aluminum, titanium and nickel of said layer form titanium carbide and nickel silicide.
Claim 12
Dependent Claim
17 words
The ohmic contact of claim 9 , wherein said noble metals are platinum, gold or palladium species.
Claim 13
Dependent Claim
24 words
The ohmic contact of claim 9 , wherein said p-type SiC substrate is a part of multilayer epitaxial structure or single crystal of SiC.
Claim 14
Dependent Claim
22 words
The ohmic contact of claim 9 , wherein said p-type SiC substrate has an acceptor concentration 10 18 cm −3 and higher.
Claim 15
Dependent Claim
25 words
The ohmic contact of claim 9 , wherein the contact has a specific contact resistance to SiC of less than 10 −4 ohm·cm 2 .
Claim 16
Dependent Claim
125 words
An ohmic contact to a p-type SiC substrate, comprising titanium carbide and nickel silicide, optionally containing one or more layers of one or more noble metals, wherein said contact is made by the method comprising the steps of: (A)(1) depositing a layer of aluminum, titanium and nickel, in that order, on said p-type SiC substrate to form aluminum, titanium and nickel metal contacts; (2) optionally repeating said step (A)(1) one or more times to form a series of said aluminum, titanium and nickel layers; and then, (B) heat treating the resulting article for sufficient time and at sufficient temperature to convert at least part of said deposited material to titanium carbide and nickel silicide by reaction of SiC with said titanium and nickel metal contacts.
Claim 17
Dependent Claim
125 words
An ohmic contact to a p-type SiC substrate, comprising titanium carbide and nickel silicide, optionally containing one or more layers of one or more noble metals, wherein said contact is made by the method comprising the steps of: (A)(1) depositing a layer of aluminum, titanium and nickel, in that order, on said p-type SiC substrate to form aluminum, titanium and nickel metal contacts; (2) optionally repeating said step (A)(1) one or more times to form a series of said aluminum, titanium and nickel layers; and then, (B) heat treating the resulting article for sufficient time and at sufficient temperature to convert at least part of said deposited material to titanium carbide and nickel silicide by reaction of SiC with said titanium and nickel metal contacts.
Claim 18
Dependent Claim
29 words
The ohmic contact of claim 14 , wherein said heat treatment is carried out at a temperature in the range of from about 850° C. to about 1150° C.
Claim 19
Dependent Claim
25 words
The ohmic contact of claim 14 , wherein one or more layers of noble metals are deposited in between said titanium and nickel contact metals.
Claim 20
Dependent Claim
17 words
The ohmic contact of claim 14 , wherein said noble metals are platinum, gold or palladium species.
Claim 21
Dependent Claim
38 words
The ohmic contact of claim 14 or 16 , wherein at least one of said depositing layers is formed using a method selected from the group consisting of chemical vapor deposition, sputtering and evaporation from a metal source.
Claim 22
Dependent Claim
23 words
The ohmic contact of claim 9 , wherein said ohmic contact additionally contains one or more layers of one or more noble metals.
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