Conductive element with lateral oxidation barrier

• US 7,330,494 B1
• Filed: 04/25/2000
• Issued: 02/12/2008
• Est. Priority Date: 12/18/1995
• Status: Expired due to Fees

• Current Assignee: Lumentum Operations, LLC (Lumentum Holdings Inc.)
• Original Assignee: Viavi Solutions, Inc. (Lumentum Holdings Inc.)
• Inventors: Jewell, Jack L.
• Primary Examiner(s): Harvey; Minsun Oh
• Assistant Examiner(s): Nguyen; Phillip
• Application Number:
  US09/557,289
• Time in Patent Office: 2,849 Days
• Field of Search: 372 43- 46, 372 92- 96, 372/50.1, 372/50.124, 372/98
• US Class Current: 372/50.124
• CPC Class Codes: H01L 33/145 with a current-blocking structure
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/18333 only above the active layer
• CPC Class Codes: H01S 5/18341 Intra-cavity contacts
• CPC Class Codes: H01S 5/18372 by native oxidation
• CPC Class Codes: H01S 5/22 having a ridge or stripe structure
• CPC Class Codes: H01S 5/2215 using native oxidation of semiconductor layers
• CPC Class Codes: H01S 5/4087 emitting more than one wavelength
• CPC Class Codes: H01S 5/423 having a vertical cavity

Abstract

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.

Claims

1. A laser structure, comprising:

an active region;

a first electrical contact disposed on a first surface of said laser structure;

a second electrical contact, said active region being disposed between said first and second electrical contacts;

a first oxidizable layer, said first oxidizable layer being subject to physical change when exposed to an oxidizing agent;

means for selectively exposing a portion of said first oxidizable layer to said oxidizing agent;

a first unchanged region of said first oxidizable layer surrounded by a first changed region of said first oxidizable layer, said first unchanged region of said first oxidizable layer being aligned with a preselected region of said active region, said first changed region being electrically insulative, said first unchanged region being electrically conductive;

wherein said means for selectively exposing includes at least one pit extending from said first surface of said laser structure into the body of said laser structure and through said first oxidizable layer to expose a portion of said oxidizable layer to said oxidizing agent during manufacture of said laser structure.

2. The laser structure of claim 1, wherein:

said laser structure is a vertical cavity surface emitting laser.

3. The laser structure of claim 1, further comprising:

a second oxidizable layer, said second oxidizable layer being subject to change when exposed to said oxidizing agent;

means for selectively exposing a portion of said second oxidizable layer to said oxidizing agent;

a second unchanged region of said second oxidizable layer surrounded by a second changed region of said second oxidizable layer, said second unchanged region of said second oxidizable layer being aligned with said preselected region of said active region, said second changed region being electrically insulative, said second unchanged region being electrically conductive, said first and second unchanged regions being aligned with each other to define a current channel extending through said preselected region of said active region; and

said means for selectively exposing a portion of said second oxidizable layer further comprises at least one pit extending from said first surface of said laser into the body of said laser structure and through said second oxidizable layer to expose a portion of said second oxidizable layer to said oxidizing agent during manufacture of said laser structure.

4. The laser structure of claim 1, wherein:

said laser structure comprises a substrate portion, a lasing portion disposed on said substrate portion, a contact support portion disposed on said substrate portion, and a bridging portion disposed on said substrate portion, said bridging portion connected between said lasing portion and said contact support portion, said first oxidizable layer being exposed at a surface of said lasing portion.

5. The laser structure of claim 3, wherein:

said laser structure comprises a substrate portion, a lasing portion disposed on said substrate portion, a contact support portion disposed on said substrate portion, and a bridging portion disposed on said substrate portion, said bridging portion connected between said lasing portion and said contact support portion, said first and second oxidizable layers being exposed at a surface of said lasing portion.

6. The laser structure of claim 1, wherein said physical change is oxidation.

7. The laser structure of claim 6, wherein:

said oxidizing agent is water vapor.

8. The laser structure of claim 1, wherein said means for selectively exposing further comprises:

four pits extending from said first surface of said laser structure into the body of said laser structure and through said first oxidizable layer to expose a plurality of portions of said oxidizable layer to said oxidizing agent during manufacture of said laser structure.

9. The laser structure of claim 1, further comprising:

a first mirror structure comprising a first plurality of layers;

a second mirror structure comprising a second plurality of layers, said active region being disposed between said first and second mirror structures.

10. The laser structure of claim 3, wherein:

said means for selectively exposing a portion of said second oxidizable layer further comprises four pits extending from said first surface of said laser structure into the body of said laser structure and through said second oxidizable layer to expose a plurality of portions of said second oxidizable layer to said oxidizing agent during manufacture of said laser structure.

11. A laser structure, comprising:

an active region;

a first electrical contact disposed on a first surface of said laser structure;

a second electrical contact, said active region being disposed between said first and second electrical contacts, said laser structure being a vertical cavity surface emitting laser;

a first oxidizable layer, said first oxidizable layer being subject to oxidation when exposed to an oxidizing agent;

a second oxidizable layer, said second oxidizable layer being subject to oxidation when exposed to said oxidizing agent;

first means for selectively exposing a portion of said first oxidizable layer to said oxidizing agent;

a first nonoxidizable region of said first oxidizable layer surrounded by a first oxidizable region of said first oxidizable layer, said first nonoxidizable region of said first oxidizable layer being aligned with a preselected region of said active region, said first oxidizable region being electrically insulative, said first nonoxidizable region being electrically conductive;

second means for selectively exposing a portion of said second oxidizable layer to said oxidizing agent;

second nonoxidizable region of said second oxidizable layer surrounded by a second oxidizable region of said second oxidizable layer, said second nonoxidizing region of said second oxidizable layer being aligned with said preselected region of said active region, said second oxidizable region being electrically insulative, said second nonoxidizable region being electrically conductive, said first and second nonoxidizable regions being aligned with each other to define a current channel extending through said preselected region of said active region; and

wherein said first means for selectively exposing and said second means for selectively exposing include at least one pit extending from said first surface of said laser structure into the body of said laser structure and through said first and second oxidizable layers to expose a portion of said first and second oxidizable layers to said oxidizing agent during manufacture of said laser structure.

12. The laser structure of claim 11, wherein:

said laser structure comprises a substrate portion, a lasing portion disposed on said substrate portion, a contact support portion disposed on said substrate portion, and a bridging portion disposed on said substrate portion, said bridging portion connected between said lasing portion and said contact support portion, said first and second oxidizable layers being exposed at a surface of said lasing portion.

13. The laser structure of claim 12, wherein:

said first and second oxidizable layers comprise an aluminum bearing material.

14. The laser structure of claim 12, wherein:

said oxidizing agent is water vapor.

15. The laser structure of claim 11, wherein:

said first and second means for selectively exposing further include four pits extending from said first surface of said laser structure into the body of said laser structure and through said first and second oxidizable layers to expose a plurality of portions of said oxidizable layers to said oxidizing agent during manufacture of said laser structure.

16. A laser structure, comprising:

an active region;

a first electrical contact disposed on a first surface of said laser structure;

a second electrical contact, said active region being disposed between said first and second electrical contacts, said laser structure being a vertical cavity surface emitting laser;

a first oxidizable layer, said first oxidizable layer being subject to oxidation when exposed to an oxidizing agent;

a second oxidizable layer, said second oxidizable layer being subject to oxidation when exposed to said oxidizing agent;

first means for selectively exposing a portion of said first oxidizable layer to said oxidizing agent;

a first nonoxidizable region of said first layer surrounded by a first oxidizable region of said first oxidizable layer, said first nonoxidizable region of said first oxidizable layer being aligned with a preselected region of said active region, said first oxidizable region being electrically insulative, said first nonoxidizable region being electrically conductive;

second means for selectively exposing a portion of said second oxidizable layer to said oxidizing agent;

a second nonoxidizable region of said second oxidizable layer surrounded by a second oxidizable region of said second oxidizable layer, said second nonoxidizable region of said second oxidizable layer being aligned with said preselected region of said active region, said second oxidizable region being electrically insulative, said second nonoxidizable region being electrically conductive, said first and second nonoxidizable regions being aligned with each other to define a current channel extending through said preselected region of said active region; and

wherein said first and second means for selectively exposing further comprise at least one pit extending from said first surfaces of said laser structure into the body of said laser structure and through said first and second oxidizable layers to expose a portion of said oxidizable layers to said oxidizing agent during manufacture of said laser structure.

17. The laser structure of claim 16, wherein:

said laser structure comprises a substrate portion, a lasing portion disposed on said substrate portion, a contact support portion disposed on said substrate portion, and a bridging portion disposed on said substrate portion, said bridging portion connected between said lasing portion and said contact support portion, said first and second oxidizable layers being exposed at a surface of said lasing portion, said first and second oxidizable layers comprise an aluminum bearing material, said oxidizing agent being water vapor.

18. The laser structure of claim 16, further comprising:

a plurality of pits extending from said first surface of said laser structure into the body of said laser structure and through said first oxidizable layer to expose a plurality of portions of said oxidizable layer to said oxidizing agent during manufacture of said laser structure.

19. The laser structure of claim 16, wherein:

the first and second means for exposing further include four pits extending from said first surface of said laser structure into the body of said laser structure and through said first and second oxidizable layers to expose a plurality of portions of said oxidizable layers to said oxidizing agent during manufacture of said laser structure.