Light emitting diode array and production method of the light emitting diode
First Claim
1. A light emitting diode array comprising:
- a substrate crystal made of a first conductivity-type semi-conductor;
a plurality of light emitting diodes aligned in row on the substrate crystal, each of the light emitting diodes having a light output surface from which a light is emitted outside, and being isolated with isolating mesa grooves, and having a double hetero-structure formed by causing a light emitting layer having a forbidden band width to be interposed between a first semi-conductor layer of said first conductivity-type and a second semi-conductor layer of a second conductivity-type; and
a reflecting layer provided between the substrate crystal and one of said first and second semi-conductor layers, the reflecting layer comprising a plurality of semi-conductive layers having 2 or more different refractive indexes, each of the semi-conductive layers having the same conductivity-type as that of the substrate crystal and having a wider forbidden band width than that of the light emitting layer.
2 Assignments
0 Petitions
Accused Products
Abstract
An LED (light emitting diode) array of the present invention has a plurality of light emitting diodes aligned in row on a substrate crystal. Each of the light emitting diodes has a double hetero-structure formed by causing a light emitting layer to be interposed between p-type and n-type semi-conductive layers and is isolated with isolating mesa grooves. A reflecting layer is provided between the substrate crystal and one of the p-type and n-type semi-conductive layers. The reflecting layer comprises a plurality of semi-conductive layers having at least different refractive indexes of 2 or more than 2-kinds, each of the semi-conductive layers made of semiconductor having the same polarity as that of the substrate crystal and having a wider forbidden band width than that of the light emitting layer. Further, the isolating mesa grooves are provided by a wet etching using an etching liquid of H3 PO4 ·H2 O2 having volume ratio of H3 PO4 : H2 O2 =1˜5:1, thus, the LED array having a high integration and a high light emitting output can be successfully produced.
156 Citations
10 Claims
-
1. A light emitting diode array comprising:
-
a substrate crystal made of a first conductivity-type semi-conductor; a plurality of light emitting diodes aligned in row on the substrate crystal, each of the light emitting diodes having a light output surface from which a light is emitted outside, and being isolated with isolating mesa grooves, and having a double hetero-structure formed by causing a light emitting layer having a forbidden band width to be interposed between a first semi-conductor layer of said first conductivity-type and a second semi-conductor layer of a second conductivity-type; and a reflecting layer provided between the substrate crystal and one of said first and second semi-conductor layers, the reflecting layer comprising a plurality of semi-conductive layers having 2 or more different refractive indexes, each of the semi-conductive layers having the same conductivity-type as that of the substrate crystal and having a wider forbidden band width than that of the light emitting layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
5. A light emitting diode array as claimed in claim 1, wherein the other of said first and second semi-conductor layers of the double hetero-structure which is provided between the light emitting surface and the light emitting layer, comprises a plurality of semi-conductive layers having different conductivities, at least one of the plurality of semi-conductive layers which are provided on the side of the light emitting surface having a higher conductivity than those of remainders of the plurality of semi-conductive layers.
-
6. A light emitting diode array as claimed in claim 1, wherein the reflecting layer is made of a multiplexed reflecting multilayer having a plurality of reflecting multilayers each having a different reflective center wavelength, each of the plurality of the multilayers being formed in such a manner that a plurality of semi-conductive layers having 2 or more different refractive indexes are stacked alternately.
-
7. A light emitting diode array as claimed in claim 6, wherein respective semi-conductor layers of the same refractive index have different thicknesses among said plurality of reflecting multilayers.
-
8. A light emitting diode array as claimed in claim 1, further comprising parallel grooves extended in parallel with a direction of the light emitting diodes aligned in row, the parallel grooves being defined as positive-type mesa grooves, and the isolating mesa grooves being defined as positive-type mesa grooves.
-
9. A light emitting diode array as claimed in claim 1, further comprising parallel grooves provided in parallel with a direction of the light emitting diodes aligned in row, the parallel grooves being define as positive-type mesa grooves, and each of the isolating mesa grooves comprising a positive-type groove defined from the top of the light output surface of the light emitting diode array to a p-n junction plane formed between the one of said first and second semi-conductor layers and the light emitting layer, and a negative-type mesa grooves defined in a deeper portion than the p-n junction plane.
-
10. A light emitting diode array as claimed in claim 1, further comprising parallel grooves provided in parallel with a direction of the light emitting diodes aligned in row, the parallel grooves being defined as positive-type mesa grooves, and each of the isolating mesa grooves having perpendicular walls perpendicular to an upper surface of the substrate crystal.
-
Specification