US5008718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light-emitting diode with an electrically conductive window
Assignee: Lumileds LLC
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Filing: 1989-12-18
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Granted: 1991-04-16
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Expires: 2009-12-18
Abstract
Abstract A light-emitting diode has a semiconductor substrate underlying active p-n junction layers of AlGaInP for emitting light. A transparent window layer of semiconductor different from AlGaInP overlies the active layers and has a lower electrical resistivity than the active layers and a bandgap greater than the bandgap of the active layers, for minimizing current crowding from a metal electrical contact over the transparent window layer. The active layers may be epitaxially grown on a temporary GaAs substrate. A layer of lattice mismatched GaP is then grown on the active layers with the GaP having a bandgap greater than the bandgap of the active layers so that it is transparent to light emitted by the LED. The GaAs temporary substrate is then selectively etched away so that the GaP acts as a transparent substrate. A transparent window layer may be epitaxially grown over the active layers on the face previously adjacent to the GaAs substrate.
Inventors
- 👤 Robert M. Fletcher
- 👤 Chihping Kuo
- 👤 Timothy D. Osentowski
- 👤 Virginia M. Robbins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:32
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/80; H10H20/81; H10H20/822; H10H20/824; H10H20/01; H10H20/011; H10H20/013
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
71 words
A light emitting diode comprising: a semiconductor substrate; an electrical contact to the substrate; active p-n junction layers for AlGaInP over the substrate for emitting light; a transparent window layer of semiconductor different from AlGaInP over the active layers and having a bandgap greater than the bandgap of the active layers and a resistivity lower than the active layers; and a metal electrical contact over a portion of the transparent layer.
Claim 2
Dependent Claim
71 words
A light emitting diode comprising: a semiconductor substrate; an electrical contact to the substrate; active p-n junction layers for AlGaInP over the substrate for emitting light; a transparent window layer of semiconductor different from AlGaInP over the active layers and having a bandgap greater than the bandgap of the active layers and a resistivity lower than the active layers; and a metal electrical contact over a portion of the transparent layer.
Claim 3
Dependent Claim
16 words
A light emitting diode as recited in claim 1 wherein the transparent window layer comprises GaAsP.
Claim 4
Dependent Claim
16 words
A light emitting diode as recited in claim 1 wherein the transparent window layer comprises GaP.
Claim 5
Dependent Claim
16 words
A light emitting diode as recited in claim 1 wherein the transparent window layer comprises AlGaAs.
Claim 6
Dependent Claim
18 words
A light emitting diode as recited in claim 1 wherein the transparent window layer comprises a p-type semiconductor.
Claim 7
Dependent Claim
30 words
A light emitting diode as recited in claim 1 wherein the transparent window layer has a resistivity at least an order of magnitude less than the resistivity of the AlGaInP.
Claim 8
Dependent Claim
14 words
A light emitting diode as recited in claim 1 wherein the substrate comprises GaAs.
Claim 9
Dependent Claim
104 words
A light emitting diode comprising: an opaque semiconductor substrate; an electrical contact to the substrate; a first confining layer of a first conductivity type AlGaInP on the substrate; an active layer of a first conductivity type AlGaInP on the first confining layer; a second confining layer of a second conductivity type AlGaInP on the active layer; a transparent window layer of semiconductor different from AlGaInP over the second confining layer and having a lower resistivity than the second confining layer and a bandgap greater than the bandgap of the active layer; and a metal electrical contact over a portion of the transparent window layer.
Claim 10
Dependent Claim
104 words
A light emitting diode comprising: an opaque semiconductor substrate; an electrical contact to the substrate; a first confining layer of a first conductivity type AlGaInP on the substrate; an active layer of a first conductivity type AlGaInP on the first confining layer; a second confining layer of a second conductivity type AlGaInP on the active layer; a transparent window layer of semiconductor different from AlGaInP over the second confining layer and having a lower resistivity than the second confining layer and a bandgap greater than the bandgap of the active layer; and a metal electrical contact over a portion of the transparent window layer.
Claim 11
Dependent Claim
16 words
A light emitting diode as recited in claim 8 wherein the transparent window layer comprises GaAsP.
Claim 12
Dependent Claim
16 words
A light emitting diode as recited in claim 8 wherein the transparent window layer comprises GaP.
Claim 13
Dependent Claim
16 words
A light emitting diode as recited in claim 8 wherein the transparent window layer comprises AlGaAs.
Claim 14
Dependent Claim
20 words
A light emitting diode as recited in claim 8 wherein the transparent window layer comprises a second conductivity type semiconductor.
Claim 15
Dependent Claim
30 words
A light emitting diode as recited in claim 8 wherein the transparent window layer has a resistivity at least an order of magnitude less than the resistivity of the AlGaInP.
Claim 16
Dependent Claim
14 words
A light emitting diode as recited in claim 8 wherein the substrate comprises GaAs.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-04-15 | 1994-10-15 | 1995-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-04-15 | 1998-10-15 | 1999-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-04-15 | 2002-10-15 | 2003-04-16 | $7700.00 | Window Closed / Lapsed |