US6319757B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adhesion and/or encapsulation of silicon carbide-based semiconductor devices on ceramic substrates
Assignee: Microsemi Corp
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Filing: 1999-07-06
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Granted: 2001-11-20
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Expires: 2019-07-06
Abstract
Abstract A SiC die with Os and/or W/WC/TiC contacts and metal conductors is encapsulated either alone or on a ceramic substrate using a borosilicate (BSG) glass that is formed at a temperature well below upper device operating temperature limits but serves as a stable protective layer above the operating temperature (over 1000° C., preferably >1200° C.). The glass is preferably 30-50% B 2 O 3 /70-50% SiO 2 , formed by reacting a mixed powder, slurry or paste of the components at 460°-1000° C. preferably about 700° C. The die can be mounted on the ceramic substrate using the BSG as an adhesive. Metal conductors on the ceramic substrate are also protected by the BSG. The preferred ceramic substrate is AlN but SiC/AlN or Al 2 O 3 can be used.
Inventors
- 👤 James D. Parsons
- 👤 B. Leo Kwak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:32
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0115; H10D64/012; H10D64/0121; H10D64/0123; H10W; H10W74/00; H10W74/40; H10W74/43; H10W72/00; H10W72/071; H10W72/073; H10W72/07331; H10W72/07337; H10W72/30; H10W72/351; H10W72/353; H10W72/354; Y; Y10; Y10S; Y10S438/00; Y10S438/931
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
79 words
A method for the protective encapsulation of a semiconductor device having at least one silicon carbide-containing layer, which comprises the steps of (a) providing a silicon carbide-containing semiconductor substrate having a first and second major surface; and (b) coating at least one of the first and second major surface of the silicon carbide-containing semiconductor substrate with a stable encapsulating layer which protects the semiconductor device from mechanical degradation and from thermal degradation at a temperature greater than 1000° C.
Claim 2
Independent Claim
79 words
A method for the protective encapsulation of a semiconductor device having at least one silicon carbide-containing layer, which comprises the steps of (a) providing a silicon carbide-containing semiconductor substrate having a first and second major surface; and (b) coating at least one of the first and second major surface of the silicon carbide-containing semiconductor substrate with a stable encapsulating layer which protects the semiconductor device from mechanical degradation and from thermal degradation at a temperature greater than 1000° C.
Claim 3
Dependent Claim
22 words
A method according to claim 1 , wherein the stable encapsulating layer is formed at a temperature of less than 1000° C.
Claim 4
Dependent Claim
31 words
A method according to claim 1 , wherein said silicon carbide-containing layer includes metal contacts or circuitry which is protected against the effects of substantial oxidization/reduction thereof by the encapsulation layer.
Claim 5
Dependent Claim
29 words
A method according to claim 1 , wherein said semiconductor device and said encapsulation layer resists thermal shock in a temperature range of from −200° C. to 1100° C.
Claim 6
Dependent Claim
49 words
A method according to claim 1 , wherein the stable encapsulating layer is a glass which is formed at a temperature less than 1000° C. and which protect the surfaces and structures of said carbide-containing semiconductor substrate from mechanical degradation and from thermal degradation at temperatures above 1000° C.
Claim 7
Dependent Claim
14 words
A method according to claim 5 , wherein the glass is a borosilicate glass.
Claim 8
Dependent Claim
34 words
A method according to claim 6 , wherein the composition of said glass comprises 30 to 50 weight % of B 2 O 3 and 70 to 50 weight % Of SiO 2 .
Claim 9
Dependent Claim
20 words
A method according to claim 1 , wherein the silicon carbide-containing semiconductor substrate comprises contacts formed of WC and TiC.
Claim 10
Dependent Claim
18 words
A method according to claim 1 , wherein the silicon carbide-containing semiconductor substrate comprises contacts formed of Os.
Claim 11
Dependent Claim
31 words
A method according to claim 1 , wherein the silicon carbide-containing semiconductor substrate comprises conductors coupled to contacts which are formed of one of W, Pt, Pd, Au, Pt/Au, and Pd/Au.
Claim 12
Dependent Claim
28 words
A method according to claim 1 , wherein the stable encapsulating layer protects metal contacts and circuits on any one of a silicon carbide, oxide and nitride surface.
Claim 13
Dependent Claim
55 words
A method according to claim 1 , wherein the stable encapsulating layer is formed by applying an unreacted powdery material to one of the first and second major surface of said silicon carbide-containing semiconductor substrate, and heating the unreacted powdery material to a temperature less than 1000° C. which will form the stable encapsulating layer.
Claim 14
Dependent Claim
23 words
A method according to claim 1 , wherein the stable encapsulating layer is formed at a temperature of about 700° C. or less.
Claim 15
Dependent Claim
27 words
A method according to claim 1 , wherein the stable encapsulating layer is bonded to the first and second major surface of the silicon carbide-containing semiconductor substrate.
Claim 16
Dependent Claim
31 words
A method according to claim 14 , wherein the bond formed between the encapsulating layer and the silicon carbide-containing semiconductor substrate is non-invasive with respective to the silicon carbide-containing semiconductor substrate.
Claim 17
Dependent Claim
27 words
A method according to claim 15 , wherein the stable encapsulating layer is immune to thermal shock in the temperature range of up to about 1100° C.
Claim 18
Dependent Claim
14 words
A method according to claim 15 , wherein the encapsulating layer is electrically insulating.
Claim 19
Dependent Claim
19 words
A method according to claim 15 , wherein the Si carbide-containing semiconductor substrate is bonded to an underlying substrate.
Claim 20
Dependent Claim
16 words
A method according to claim 15 , wherein the underlying substrate comprises a layer of AIN.
Claim 21
Dependent Claim
18 words
A method according to claim 16 , wherein the expansion coefficients of AlN and SiC are nearly identical.
Claim 22
Dependent Claim
17 words
A method according to claim 15 , wherein the underlying substrate comprises a layer of polycrystalline AlN.
Claim 23
Dependent Claim
20 words
A method according to claim 15 , wherein the underlying substrate comprises a layer of AlN on a SiC substrate.
Claim 24
Independent Claim
108 words
A method for the adhesion of a SiC-containing substrate to an underlying substrate in the formation of a semiconductor device, which comprises the steps of: (a) providing said SiC-containing substrate having a first and second major surface; (b) providing said underlying substrate having a first and second major surface; and (c) bonding with a bonding material one of the first and second major surface of said SiC-containing substrate to one of the first and second major surface of said underlying substrate, said bonded SiC-containing substrate-underlying substrate structure being adhered to the underlying substrate without substantial mechanical or thermal degradation at temperatures up to at least about 1000° C.
Claim 25
Independent Claim
108 words
A method for the adhesion of a SiC-containing substrate to an underlying substrate in the formation of a semiconductor device, which comprises the steps of: (a) providing said SiC-containing substrate having a first and second major surface; (b) providing said underlying substrate having a first and second major surface; and (c) bonding with a bonding material one of the first and second major surface of said SiC-containing substrate to one of the first and second major surface of said underlying substrate, said bonded SiC-containing substrate-underlying substrate structure being adhered to the underlying substrate without substantial mechanical or thermal degradation at temperatures up to at least about 1000° C.
Claim 26
Dependent Claim
31 words
A method according to claim 23 , wherein said SiC-containing substrate is bonded to said underlying substrate at a temperature of greater than 460° C. and less than about 1000° C.
Claim 27
Dependent Claim
37 words
A method according to claim 23 , wherein said semiconductor device including said SiC-containing substrate bonded to said underlying substrate does not undergo substantial thermal shock in a temperature range of from −200° C. to 1100° C.
Claim 28
Dependent Claim
31 words
A method according to claim 23 , wherein the bonding material is a glass which will not undergo mechanical degradation and thermal degradation at temperatures above at least about 1000° C.
Claim 29
Dependent Claim
14 words
A method according to claim 26 , wherein the glass is a borosilicate glass.
Claim 30
Dependent Claim
34 words
A method according to claim 24 , wherein the composition of said glass comprises 30 to 50 weight % of B 2 O 3 and 70 to 50 weight % of SiO 2 .
Claim 31
Dependent Claim
32 words
A method according to claim 23 , wherein the bonding material forms a stable encapsulating layer which protects metal contacts and circuits on any one of a silicon-carbide, -oxide and -nitride surface.
Claim 32
Dependent Claim
46 words
A method according to claim 23 , wherein the bonding material is formed by applying an unreacted powdery material to one of the first and second major surface of said silicon carbide-containing semiconductor substrate, and heating the unreacted powdery material to at least its bonding temperature.
Claim 33
Dependent Claim
18 words
A method according to claim 23 , wherein bonding is effected at a temperature of about 700° C.
Claim 34
Dependent Claim
29 words
A method according to claim 23 , wherein bonding of the silicon carbide-containing semiconductor substrate to the underlying substrate is non-invasive with respect to the silicon carbide-containing semiconductor substrate.
Claim 35
Dependent Claim
22 words
A method according to claim 23 , wherein the SiC-containing substrate is SiC and the underlying substrate includes a layer of AlN.
Claim 36
Dependent Claim
18 words
A method according to claim 23 , wherein the expansion coefficients of AlN and SiC are nearly identical.
Claim 37
Independent Claim
137 words
A method for the protective encapsulation and adhesion of a SiC-containing substrate and an underlying substrate, which comprises the steps of providing a Si carbide-containing semiconductor substrate having a first and second major surface; providing said underlying substrate having a first and second major surface; bonding with a bonding material at least one of the first and second major surface of said SiC-containing substrate to at least one of the first and second major surface of said underlying substrate being formed without substantial mechanical or thermal degradation at a temperature of at least 1000° C.; and coating at least one of the first and second major surface of said Si carbide-containing semiconductor substrate with a stable encapsulating layer which protects said semiconductor device from mechanical degradation and from thermal degradation at temperature of at least 1000° C.
Claim 38
Independent Claim
137 words
A method for the protective encapsulation and adhesion of a SiC-containing substrate and an underlying substrate, which comprises the steps of providing a Si carbide-containing semiconductor substrate having a first and second major surface; providing said underlying substrate having a first and second major surface; bonding with a bonding material at least one of the first and second major surface of said SiC-containing substrate to at least one of the first and second major surface of said underlying substrate being formed without substantial mechanical or thermal degradation at a temperature of at least 1000° C.; and coating at least one of the first and second major surface of said Si carbide-containing semiconductor substrate with a stable encapsulating layer which protects said semiconductor device from mechanical degradation and from thermal degradation at temperature of at least 1000° C.
Claim 39
Independent Claim
104 words
A method for the protective encapsulation of a SiC-containing substrate and an underlying substrate, which comprises the steps of (a) providing a Si carbide-containing semiconductor substrate having a first and second major surface; (b) providing said underlying substrate having a first and second major surface; and (c) coating at least one of the first and second major surface of said Si carbide-containing semiconductor substrate at a temperature of less than about 700° C. and thereby forming a stable encapsulating layer, said stable encapsulating layer protecting said semiconductor device from mechanical degradation and from thermal degradation at a temperature of at least about 1000° C.
Claim 40
Independent Claim
104 words
A method for the protective encapsulation of a SiC-containing substrate and an underlying substrate, which comprises the steps of (a) providing a Si carbide-containing semiconductor substrate having a first and second major surface; (b) providing said underlying substrate having a first and second major surface; and (c) coating at least one of the first and second major surface of said Si carbide-containing semiconductor substrate at a temperature of less than about 700° C. and thereby forming a stable encapsulating layer, said stable encapsulating layer protecting said semiconductor device from mechanical degradation and from thermal degradation at a temperature of at least about 1000° C.
Claim 41
Independent Claim
118 words
A method for adhesion of a SiC-containing substrate and an underlying substrate, which comprises the steps of (a) providing a Si carbide-containing semiconductor substrate having a first and second major surface; (b) providing said underlying substrate having a first and second major surface; and (c) bonding together with a bonding material at least one of the first and second major surface of said SiC-containing substrate to at least one of the first and second major surface of said underlying substrate, at a temperature of not more than about 700° C., said bonding together of said SiC-containing substrate to said underlying substrate being formed without substantial mechanical or thermal degradation at temperatures up to at least about 1000° C.
Claim 42
Independent Claim
118 words
A method for adhesion of a SiC-containing substrate and an underlying substrate, which comprises the steps of (a) providing a Si carbide-containing semiconductor substrate having a first and second major surface; (b) providing said underlying substrate having a first and second major surface; and (c) bonding together with a bonding material at least one of the first and second major surface of said SiC-containing substrate to at least one of the first and second major surface of said underlying substrate, at a temperature of not more than about 700° C., said bonding together of said SiC-containing substrate to said underlying substrate being formed without substantial mechanical or thermal degradation at temperatures up to at least about 1000° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-11-19 | 2005-05-21 | 2005-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-11-19 | 2009-05-21 | 2009-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-11-19 | 2013-05-21 | 2013-11-20 | $7700.00 | Window Closed / Lapsed |