US5243204A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon carbide light emitting diode and a method for the same
Assignee: Sharp Corp
•
Filing: 1991-05-17
•
Granted: 1993-09-07
•
Expires: 2011-05-17
Abstract
Abstract There are provided silicon carbide light emitting diodes having a p-n junction which is constituted by a p-type silicon carbide single-crystal layer and an n-type silicon carbide single-crystal layer formed thereon. In cases where light emission caused by recombination of free excitons is substantially utilized, at least a part of the n-type silicon carbide layer adjacent to the interface of the p-n junction is doped with a donor impurity at a concentration of 5x1016 cm-3 or lower. In cases where light emission caused by acceptor-associated recombination is substantially utilized, the p-type silicon carbide layer is doped with an acceptor impurity and at least a part of the n-type silicon carbide layer adjacent to the interface of the p-n junction is doped with a donor impurity at a concentration of 1x1018 cm-3 or higher. Also provided are a method for producing such silicon carbide light emitting diodes and a method for producting another silicon carbide light emitting diode.
Inventors
- 👤 Akira Suzuki
- 👤 Katsuki Furukawa
- 👤 Yoshihisa Fujii
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:24
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/80; H10H20/81; H10H20/822; H10H20/826; H10H20/01; H10H20/011; H10H20/014
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
95 words
A silicon carbide light emitting diode comprising an n-type silicon carbide single-crystal substrate, a second n-type silicon carbide single-crystal layer formed on the substrate, a first n-type silicon carbide single-crystal layer formed on the second n-type silicon carbide single-crystal layer and a p-type silicon carbide single-crystal layer formed on the first n-type silicon carbide single-crystal layer, wherein the second n-type layer contains a donor impurity at a concentration of higher than 5×10 16 cm -3 , and the first n-type layer contains a donor impurity at a concentration of 5×10 16 cm -3 or lower.
Claim 2
Dependent Claim
95 words
A silicon carbide light emitting diode comprising an n-type silicon carbide single-crystal substrate, a second n-type silicon carbide single-crystal layer formed on the substrate, a first n-type silicon carbide single-crystal layer formed on the second n-type silicon carbide single-crystal layer and a p-type silicon carbide single-crystal layer formed on the first n-type silicon carbide single-crystal layer, wherein the second n-type layer contains a donor impurity at a concentration of higher than 5×10 16 cm -3 , and the first n-type layer contains a donor impurity at a concentration of 5×10 16 cm -3 or lower.
Claim 3
Dependent Claim
32 words
A silicon carbide light emitting diode according to claim 1, wherein the silicon carbide single crystal is of a polytype selected from the group consisting of 4H, 6H, 15R, 21R, and 3C.
Claim 4
Dependent Claim
42 words
A silicon carbide light emitting diode according to claim 1, further comprising a substrate made of a silicon carbide single crystal in the hexagonal system, the p-type or n-type silicon carbide layer being formed on the substantial (0001)C plane of the substrate.
Claim 5
Dependent Claim
42 words
A silicon carbide light emitting diode according to claim 1, further comprising a substrate made of a silicon carbide single crystal in the cubic system, the p-type or n-type silicon carbide layer being formed on the substantial (111)C plane of the substrate.
Claim 6
Dependent Claim
48 words
A silicon carbide light emitting diode according to claim 1, wherein a surface of the n-type silicon carbide substrate on which the second n-type silicon carbide single-crystal layer is formed is inclined from the [0001] direction toward the <1120> direction at an angle of 2 to 15 degrees.
Claim 7
Dependent Claim
16 words
A silicon carbide light emitting diode according to claim 1, wherein the donor impurity is nitrogen.
Claim 8
Dependent Claim
105 words
A silicon carbide light emitting diode comprising an n-type silicon carbide single-crystal substrate, a second n-type silicon carbide single-crystal layer formed on the substrate, a first n-type silicon carbide single-crystal layer formed on the second n-type silicon carbide single-crystal layer and a p-type silicon carbide single-crystal layer formed on the first n-type silicon carbide single-crystal layer, wherein the p-type silicon carbide single-crystal layer contains an acceptor impurity, the second n-type layer contains a donor impurity at a concentration of lower than 1×10 18 cm -3 , and the first n-type layer contains a donor impurity at a concentration of 1×10 18 cm -3 or higher.
Claim 9
Dependent Claim
105 words
A silicon carbide light emitting diode comprising an n-type silicon carbide single-crystal substrate, a second n-type silicon carbide single-crystal layer formed on the substrate, a first n-type silicon carbide single-crystal layer formed on the second n-type silicon carbide single-crystal layer and a p-type silicon carbide single-crystal layer formed on the first n-type silicon carbide single-crystal layer, wherein the p-type silicon carbide single-crystal layer contains an acceptor impurity, the second n-type layer contains a donor impurity at a concentration of lower than 1×10 18 cm -3 , and the first n-type layer contains a donor impurity at a concentration of 1×10 18 cm -3 or higher.
Claim 10
Dependent Claim
30 words
A silicon carbide light emitting diode according to claim 7, wherein the silicon carbide single crystal is of a polytype selected from the group consisting of 4H, 6H, and 3C.
Claim 11
Dependent Claim
42 words
A silicon carbide light emitting diode according to claim 7, further comprising a substrate made of a silicon carbide single crystal in the hexagonal system, the p-type or n-type silicon carbide layer being formed on the substantial (0001)C plane of the substrate.
Claim 12
Dependent Claim
42 words
A silicon carbide light emitting diode according to claim 7, further comprising a substrate made of a silicon carbide single crystal in the cubic system, the p-type or n-type silicon carbide layer being formed on the substantial (111)C plane of the substrate.
Claim 13
Dependent Claim
49 words
A silicon carbide light emitting diode according to claim 7, wherein a surface of the n-type silicon carbide single-crystal substrate on which the second nj-type silicon carbide single-crystal layer is formed is inclined from the [0001] direction toward the <1120> direction at an angle of 2 to 15 degrees.
Claim 14
Dependent Claim
22 words
A silicon carbide light emitting diode according to claim 7, wherein the donor impurity is nitrogen, and the acceptor impurity is aluminum.
References Cited (Backward Citations)
US5027168A
Cited
US5061972A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-09-06 | 1997-03-08 | 1997-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-09-06 | 2001-03-08 | 2001-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-09-06 | 2005-03-08 | 2005-09-07 | $7700.00 | Window Closed / Lapsed |