OPTOELECTRONIC DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20130328102A1
• Filed: 08/14/2013
• Published: 12/12/2013
• Est. Priority Date: 10/29/2010
• Status: Active Grant

• Current Assignee: Yale University
• Original Assignee: Epistar Corporation (Ennostar, Inc.)
• Inventors: PENG, WEI CHIH, PAI, SHIH TE
• Granted Patent: US 9,070,827 B2
• Time in Patent Office: Days
• US Class Current: 257/103
• CPC Class Codes: H01L 31/0543 comprising light concentrating means of the refractive type, e.g. lenses
• CPC Class Codes: H01L 31/0547 comprising light concentrating means of the reflecting type, e.g. parabolic mirrors, concentrators using total internal reflection
• CPC Class Codes: H01L 31/075 the potential barriers being only of the PIN type, e.g. amorphous silicon PIN solar cells
• CPC Class Codes: H01L 33/0066 with a substrate not being a III-V compound
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction
• CPC Class Codes: H01L 33/305 characterised by the doping materials
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: Y02E 10/52 PV systems with concentrators
• CPC Class Codes: Y02E 10/548 Amorphous silicon PV cells

Abstract

An optoelectronic device comprising: a substrate; and an epitaxial stack including a first semiconductor layer having a first conductivity-type impurity, an active layer, and a second semiconductor layer having a second conductivity-type impurity formed in sequence on the substrate; a hollow component formed inside the active layer or the second semiconductor layer, wherein the layer with the hollow component is doped with an additional impurity.

Claims

1. An optoelectronic device comprising:

a substrate; and

an epitaxial stack including a first semiconductor layer having a first conductivity-type impurity, an active layer, and a second semiconductor layer having a second conductivity-type impurity formed in sequence on the substrate;

a hollow component formed inside the active layer or the second semiconductor layer, wherein the layer with the hollow component is doped with an additional impurity.

2. The optoelectronic device of claim 1, wherein the additional impurity being the first conductivity-type impurity.

3. The optoelectronic device of claim 1, further comprising a plurality of hollow components formed inside the active layer or the second semiconductor layer, wherein the width of one of the plurality of hollow components is between 10 nm and 2000 nm and/or the porosity of the plurality of hollow components is between 5% and 90%.

4. The optoelectronic device of claim 1, wherein the material of the first semiconductor layer, the active layer, and the second semiconductor layer contains group IIIA nitride semiconductor or group IIIA phosphide semiconductor.

5. The optoelectronic device of claim 1, wherein the second conductivity-type impurity comprise an element selected from group IIA and the additional impurity and the first conductivity-type impurity comprises an element selected from groups IVA and VIA.

6. The optoelectronic device of claim 1, wherein the doping concentration of the additional impurity is between 1E15 and 1E19 cm⁻

1.

7. The optoelectronic device of claim 1, wherein the upper surface of the second semiconductor layer has a plurality of depressions and a portion of the hollow component are exposed at sidewalls of the plurality of depressions.

8. The optoelectronic device of claim 1, wherein the plurality of hollow components is distributed at about a same level of height.

9. The optoelectronic device of claim 1, further comprising a submount, wherein the hollow component is between the submount and the substrate for reflecting a light emitted from the active layer toward the substrate.

10. A method of fabricating an optoelectronic device, comprising:

providing a substrate;

forming a first semiconductor layer having a first conductivity-type impurity on the substrate;

forming an active layer on the first semiconductor layer;

forming a second semiconductor layer having a second conductivity-type impurity;

doping an additional impurity into at least one of the second semiconductor layer and the active layer; and

forming a hollow component inside the second semiconductor layer and/or the active layer.

11. The method of fabricating an optoelectronic device of claim 10, wherein the method for forming the hollow component comprises electrochemical etching at least one of the second semiconductor layer and the active layer.

12. The method of fabricating an optoelectronic device of claim 11, wherein the electrochemical etching is performed with an aqueous solution comprising one solution selected from H₂SO₄, H₃PO₄, H₂C₂O₄, HCl, KOH, NaOH, ethylene glycol solution, and their mixture.

13. The method of fabricating an optoelectronic device of claim 10,

wherein the second conductivity-type impurity comprise an element selected from group IIA and the additional impurity and the first conductivity-type impurity comprises an element selected from groups IVA and VIA.

14. The method of fabricating an optoelectronic device of claim 10, wherein forming the second semiconductor layer comprises epitaxially growing the second semiconductor layer, and the plurality of depressions is formed during the growth of the second semiconductor layer.

15. The method of fabricating an optoelectronic device of claim 10, wherein the additional impurity is chemically more reactive to the aqueous solution of the electrochemical etching than the second conductivity-type impurity.

16. The method of fabricating an optoelectronic device of claim 15, wherein the electrochemical etching step consumes a portion of the additional impurity such that the concentration of the additional impurity is decreased after the electrochemical etching.

17. The method of fabricating an optoelectronic device of claim 10, wherein the additional impurity is doped at a depth from an upper surface of the second semiconductor layer, and the hollow component is formed about the same as the depth from the upper surface of the second semiconductor layer.

18. The method of fabricating an optoelectronic device of claim 10, wherein the additional impurity is doped during or after forming the second semiconductor layer.

19. The method of fabricating an optoelectronic device of claim 18, wherein the method for doping the additional impurity comprises ion implantation.

20. The method of fabricating an optoelectronic device of claim 10, wherein the doping temperature for doping the additional impurity is between 800 to 1200°

C.