EP0380340A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Silicon carbide Schottky diode and method of making same
Assignee: Wolfspeed Inc
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Filing: 1990-01-25
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Granted: —
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Expires: 2010-01-25
Abstract
Abstract A high performance silicon carbide Schottky contact (14) comprises a platinum containing contact on α-silicon carbide (11,12), specifically 6H-α silicon carbide. At least part (14a) of the platinum-containing contact may comprise platinum silicide which may be formed by annealing to convert at least part of the platinum to platinum silicide. An ohmic contact (13) to the substrate (11) is also provided. A guard ring (16) or field plate may be provided. The Schottky contact exhibits lower forward resistance, lower reverse current and higher reverse breakdown voltage than heretofore available designs.
Inventors
- 👤 John W. Palmour
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 17:05
CPC Classifications
H; H10; H10D; H10D8/00; H10D8/60; H10D62/00; H10D62/80; H10D62/83; H10D62/832; H10D62/8325; H10D8/01; H10D8/051
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
19 words
A Schottky contact comprising: an α-silicon carbide layer; and a platinum containing contact on said α- silicon carbide layer.
Claim 2
Dependent Claim
19 words
A Schottky contact comprising: an α-silicon carbide layer; and a platinum containing contact on said α- silicon carbide layer.
Claim 3
Dependent Claim
15 words
The Schottky contact of Claim 1 wherein said α-silicon carbide layer comprises 6H-α silicon carbide.
Claim 4
Dependent Claim
15 words
The Schottky contact of Claim 1 or 2 wherein said platinum containing contact comprises platinum.
Claim 5
Dependent Claim
16 words
The Schottky contact of Claim 1 or 2 wherein said platinum containing contact comprises platinum silicide.
Claim 6
Dependent Claim
33 words
The Schottky contact of Claim 1 or 2 wherein said platinum containing contact comprises a platinum silicide layer on said silicon carbide layer and a layer of platinum on said platinum silicide layer.
Claim 7
Dependent Claim
42 words
The Schottky contact of Claim 1 or 2 wherein said α-silicon carbide layer comprises an n+ layer of 6H-α silicon carbide and an n- layer of 6H-α silicon carbide on said n+ layer, with said platinum-containing contact being on said n- layer.
Claim 8
Dependent Claim
27 words
The Schottky contact of Claim 6 further comprising a p-type silicon carbide guard ring within said n- layer, lying under the periphery of said platinum containing contact.
Claim 9
Dependent Claim
18 words
The Schottky contact of Claim 6 further comprising a field plate at the periphery of said platinum-containing contact.
Claim 10
Dependent Claim
28 words
The Schottky contact of Claim 6, 7 or 8 further comprising an ohmic contact on an exposed side of said n+ layer, to thereby form a Schottky diode.
Claim 11
Dependent Claim
43 words
A Schottky diode comprising: an n+ 6H-α silicon carbide substrate; an ohmic contact on one side of said substrate; an n- 6H-α silicon carbide epitaxial layer on the opposite side of said substrate; and a platinum silicide Schottky contact on said n- layer.
Claim 12
Dependent Claim
43 words
A Schottky diode comprising: an n+ 6H-α silicon carbide substrate; an ohmic contact on one side of said substrate; an n- 6H-α silicon carbide epitaxial layer on the opposite side of said substrate; and a platinum silicide Schottky contact on said n- layer.
Claim 13
Dependent Claim
24 words
The Schottky diode of Claim 10 wherein said n+ layer is doped with nitrogen at a concentration greater than 10¹⁸ carriers per cubic centimeter.
Claim 14
Dependent Claim
26 words
The Schottky diode of Claim 10 or 11 wherein said n- layer is doped with nitrogen at a concentration less than 10¹⁷ carriers per cubic centimeter.
Claim 15
Dependent Claim
20 words
The Schottky diode of Claim 10, 11 or 12 wherein said platinum silicide Schottky contact is less than 2000Å thick.
Claim 16
Dependent Claim
18 words
14 . The Schottky diode of Claim 10, 11, 12 or 13 wherein said ohmic contact comprises nickel.
Claim 17
Dependent Claim
31 words
15 . A method of forming a Schottky contact comprising the steps of: providing a 6H-α silicon carbide substrate; and forming a platinum containing contact on said 6H-α silicon carbide substrate.
Claim 18
Dependent Claim
31 words
15 . A method of forming a Schottky contact comprising the steps of: providing a 6H-α silicon carbide substrate; and forming a platinum containing contact on said 6H-α silicon carbide substrate.
Claim 19
Dependent Claim
37 words
16 . The method of Claim 15 wherein said forming step comprises the steps of: forming a platinum contact on said 6H-α silicon carbide substrate; and converting at least part of said platinum contact to platinum silicide.
Claim 20
Dependent Claim
17 words
The method of Claim 16 wherein said converting step comprises the step of annealing said platinum contact.
Claim 21
Dependent Claim
29 words
The method of Claim 17 wherein said annealing step comprises the step of heating said platinum contact at a temperature of at least 600°C for at least 15 minutes.
Claim 22
Dependent Claim
22 words
The method of Claim 16 wherein said converting step comprises the step of converting all of said platinum contact to platinum silicide.
Claim 23
Dependent Claim
24 words
The method of Claim 15 wherein said forming step comprises the steps of: forming a platinum silicide contact on said 6H-α silicon carbide layer.
Claim 24
Dependent Claim
38 words
The method of Claim 15 wherein said forming step comprises the steps of: forming alternating layers of platinum and silicon on said 6H-α silicon carbide layer; and converting said alternating layers of platinum and silicon to silicon carbide.
Claim 25
Dependent Claim
49 words
The method of Claim 15 wherein said providing step comprises the steps of: providing an n+ 6H-α silicon carbide substrate; epitaxially forming an n- layer of 6H-α silicon carbide on said substrate; and wherein said forming step comprises the step of forming a platinum-containing contact on said n- layer.
References Cited (Backward Citations)
No citation records indexed.
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