PASSIVATION OF VCSEL SIDEWALLS

• US 20070254393A1
• Filed: 06/22/2007
• Published: 11/01/2007
• Est. Priority Date: 10/01/2004
• Status: Active Grant

• Current Assignee: II-VI Delaware, Inc. (Coherent Corp.)
• Original Assignee: Finisar Corporation (II-VI Incorporated)
• Inventors: Johnson, Ralph
• Granted Patent: US 8,815,617 B2
• Time in Patent Office: Days
• US Class Current: 438/38
• CPC Class Codes: H01L 33/105 with a resonant cavity structure
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01S 2301/176 Specific passivation layers on surfaces other than the emission facet
• CPC Class Codes: H01S 5/024 Arrangements for thermal management
• CPC Class Codes: H01S 5/0282 Passivation layers or treatments
• CPC Class Codes: H01S 5/0422 with n- and p-contacts on the same side of the active layer
• CPC Class Codes: H01S 5/04257 having positive and negative electrodes on the same side of the substrate
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/18341 Intra-cavity contacts
• CPC Class Codes: H01S 5/18358 containing spacer layers to adjust the phase of the light wave in the cavity
• CPC Class Codes: H01S 5/2009 by using electron barrier layers
• CPC Class Codes: H01S 5/305 characterised by the doping materials used in the laser structure
• CPC Class Codes: H01S 5/3054 p-doping
• CPC Class Codes: H01S 5/3081 using amphoteric doping
• CPC Class Codes: H01S 5/3095 Tunnel junction

Abstract

A semiconductor structure configured for use in a VCSEL or RCLED. The semiconductor structure includes an oxidizing layer constructed from materials that can be oxidized during a lithographic process so as to create an oxide aperture. The semiconductor structure further includes a number of layers near the oxidizing layer. A passivation material is disposed on the layers near the oxidizing layer. The passivation material is configured to inhibit oxidation of the layers.

Claims

1. In a manufacturing process including processing epitaxial structures for optical semiconductor devices, a method of forming an optical semiconductor device, the method comprising:

etching one or more layers above an oxidizing layer in an epitaxial structure, the oxidizing layer being constructed from materials that can be oxidized during a process so as to create an oxide aperture, wherein etching one or more layers near an oxidizing layer comprises stopping etching before the oxidizing layer is reached;

passivating at least a portion of the one or more etched layers above the oxidizing layer;

etching past at least a portion of the oxidizing layer; and

oxidizing a portion of the oxidizing layer to form an aperture in the oxidizing layer.

2. The method of claim 1, further comprising forming the one or more layers near the oxidizing layer, wherein forming the one or more layers near the oxidizing layer comprises forming the layers through epitaxy with a high aluminum content, wherein the aluminum content is defined approximately by Al(x)Ga(1−

x)As where x is approximately greater than 0.95.

3. The method of claim 1, wherein the epitaxial structure further comprises a stop etch layer, and wherein etching one or more layers near an oxidizing layer and stopping etching before the oxidizing layer is reached comprises using a etchant that is restricted from etching at the stop etch layer.

4. The method of claim 1, wherein passivating comprises depositing a layer which includes Silicon Dioxide.

5. The method of claim 1, wherein passivating comprises depositing a layer which includes Silicon Nitride.

6. The method of claim 1, further comprising forming through epitaxy a thermal conduction layer above the oxidizing layer to enhance thermal impedance characteristics of the optical semiconductor device.

7. The method of claim 1, wherein etching one or more layers above an oxidizing layer in an epitaxial structure comprises etching mirror periods.

8. The method of claim 1, wherein the optical semiconductor device is a VCSEL.

9. The method of claim 1, wherein the optical semiconductor device is an RCLED.

10. A semiconductor structure configured for use in an optical semiconductor device comprising:

an oxidizing layer constructed from materials that can be oxidized during a process so as to create an oxide aperture;

a plurality of layers near the oxidizing layer; and

a passivation material disposed on the plurality of layers above the oxidizing layer, the passivation material configured to inhibit oxidation of the plurality of layers.

11. The semiconductor structure of claim 10, wherein the passivation material is not disposed on the oxidizing layer allowing the oxidizing layer to be oxidized to form the oxide aperture in the oxidizing layer.

12. The semiconductor structure of claim 10, wherein the plurality of layers above the oxidizing layer comprise a DBR mirror.

13. The semiconductor structure of claim 10, wherein the plurality of layers above the oxidizing layer comprise one or more layers with a composition defined approximately by Al(x)Ga(1−

x)As where x is approximately greater than 0.95.

14. The semiconductor structure of claim 10, further comprising a thermal conduction layer above the oxidizing layer and wherein the passivation material is disposed on the thermal conduction layer.

15. The semiconductor structure of claim 10, further comprising a thermal conduction layer between the oxidizing layer and the plurality of layers, wherein the passivation material is disposed on the thermal conduction layer.

16. The semiconductor structure of claim 10, further comprising a stop etch layer between the oxidizing layer and the plurality of layers configured to allow etching to be performed on the plurality of layers on not the oxidizing layer such that the passivation material can be deposited on the plurality of layers before etching to the oxidizing layer.

17. The semiconductor structure of claim 10, wherein the passivation material is Silicon Nitride.

18. The semiconductor structure of claim 10, wherein the passivation material is Silicon Dioxide.

19. The semiconductor structure of claim 10, wherein the optical semiconductor device is a VCSEL.

20. The semiconductor structure of claim 10, wherein the optical semiconductor device is an RCLED.