Conductive element with lateral oxidation barrier
View Patent ↗A conductive element with a lateral oxidation barrier is provided for the control of lateral oxidation processes in semiconductor devices such as lasers, vertical cavity surface emitting lasers and light emitting diodes. The oxidation barrier is formed through modification of one or more layers which initially were receptive to oxidation. The quality of material directly below the oxidation barrier may be preserved. Related applications include the formation of vertical cavity surface emitting lasers on non-GaAs substrates and on GaAs substrates.
1. A surface emitting laser having a light emitting surface, said laser comprising:
a substrate;
a plurality of semiconductor layers formed on said substrate;
one of said semiconductor layers comprising an active layer having an active region therein;
a first reflector located on one side of said active layer and a second reflector located on the opposite side of said active layer, at least one of said reflectors allowing a partial transmission of light energy therethrough;
one of said semiconductor layers being a current controlling layer, said current controlling layer being penetrated by a plurality of hollow cavities;
an aperture region in said current controlling layer which controls current flowing through said active region, said aperture region being defined by a conductive region in said current controlling layer bordered by non-conductive regions in said current controlling layer, and wherein one of said non-conductive regions surrounds one of said plurality of hollow cavities; and
first and second electrodes located on said laser device to enable biasing of said active region.
2. The surface emitting laser of claim 1 wherein each of said plurality of hollow cavities is a hole.
3. The surface emitting laser of claim 1 wherein said current controlling layer is an oxidation layer, said conductive region is an unoxidized portion of said oxidation layer, and said non-conductive regions are oxidized portions of said oxidation layer.
4. The surface emitting laser of claim 3 wherein said oxidation layer comprises an aluminum containing semiconductor layer.
5. The surface emitting laser of claim 1 wherein said first electrode is located on said emitting surface and overlies said aperture region.
6. The surface emitting laser of claim 5 wherein said first electrode is non-transparent and includes an opening therein through which light energy may be transmitted out of the laser.
7. The surface emitting laser of claim 1 wherein said plurality of semiconductor layers comprises a Group III-V arsenide material.
8. An array of surface emitting lasers, wherein each of said surface emitting lasers comprises a device in accordance with claim 1 .
9. A surface emitting laser having a light emitting surface, said laser comprising:
a substrate;
a plurality of semiconductor layers formed on said substrate;
one of said semiconductor layers comprising an active layer having an active region therein;
a first reflector located on one side of said active layer and a second reflector located on the opposite side of said active layer, at least one of said reflectors allowing a partial transmission of light energy therethrough;
one of said semiconductor layers being a current controlling layer, said current controlling layer being penetrated by a plurality of hollow cavities, each of said hollow cavities having a substantially rectangular opening;
an aperture region in said current controlling layer which controls current flowing through said active region, said aperture region being defined by a conductive region in said current controlling layer bordered by non-conductive regions in said current controlling layer, and wherein one of said non-conductive regions surrounds one of said hollow cavities; and
first and second electrodes located on said laser device to enable biasing of said active region.
10. The surface emitting laser of claim 9 wherein said current controlling layer is an oxidation layer, said conductive region is an unoxidized portion of said oxidation layer, and said non-conductive regions are oxidized portions of said oxidation layer.
11. The surface emitting laser of claim 10 wherein said oxidation layer comprises an aluminum containing semiconductor layer.
12. The surface emitting laser of claim 9 wherein said first electrode is non-transparent and includes an opening therein through which light energy may be transmitted out of the laser.
13. The surface emitting laser of claim 9 wherein said plurality of semiconductor layers comprises a Group III-V arsenide material.
14. A surface emitting laser having a light emitting surface, said laser comprising:
a substrate;
a plurality of semiconductor layers formed on said substrate;
one of said semiconductor layers comprising an active layer having an active region therein;
a first reflector located on one side of said active layer and a second reflector located on the opposite side of said active layer, at least one of said reflectors allowing a partial transmission of light energy therethrough;
one of said semiconductor layers being a current controlling layer, said current controlling layer being penetrated by two hollow cavities, each of said hollow cavities having a substantially rectangular opening;
an aperture region in said current controlling layer which controls current flowing through said active region, said aperture region being defined by a conductive region in said current controlling layer bordered by non-conductive regions in said current controlling layer, and wherein one of said non-conductive regions surrounds one of said hollow cavities; and
first and second electrodes located on said laser device to enable biasing of said active region.