METHOD OF SEPARATING NITRIDE FILMS FROM GROWTH SUBSTRATES BY SELECTIVE PHOTO-ENHANCED WET OXIDATION AND ASSOCIATED SEMICONDUCTOR STRUCTURE

• US 20130228807A1
• Filed: 04/09/2013
• Published: 09/05/2013
• Est. Priority Date: 04/14/2011
• Status: Active Grant

• Current Assignee: Opto Tech Corporation (OptoTech Corp.)
• Original Assignee: Opto Tech Corporation (OptoTech Corp.)
• Inventors: Peng, Lung-Han, Yu, Jeng-Wei, Yeh, Po-Chun
• Granted Patent: US 8,679,883 B2
• Time in Patent Office: Days
• US Class Current: 257/95
• CPC Class Codes: H01L 21/268 using electromagnetic radiation, e.g. laser radiation
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

Various embodiments of the present disclosure pertain to selective photo-enhanced wet oxidation for nitride layer regrowth on substrates. In one aspect, a semiconductor structure may comprise: a first substrate structure; a III-nitride structure bonded with the first substrate structure; a plurality of air gaps formed between the first substrate structure and the III-nitride structure; and a III-oxide layer formed on surfaces around the air gaps, wherein a portion of the III-nitride structure including surfaces around the air gaps is transformed into the III-oxide layer by a selective photo-enhanced wet oxidation, and the III-oxide layer is formed between an untransformed portion of the III-nitride structure and the first substrate structure.

Claims

1. A semiconductor structure comprising:

a first substrate structure;

a III-nitride structure bonded with the first substrate structure;

a plurality of air gaps formed between the first substrate structure and the III-nitride structure; and

a III-oxide layer formed on surfaces around the air gaps, wherein a portion of the III-nitride structure including surfaces around the air gaps is transformed into the III-oxide layer by a selective photo-enhanced wet oxidation, and the III-oxide layer is formed between an untransformed portion of the III-nitride structure and the first substrate structure.

2. The semiconductor structure as recited in claim 1, wherein the first substrate structure comprises a substrate and at least a first III-nitride layer having a first high bandgap energy on the substrate, and wherein the III-nitride structure comprises at least a second III-nitride layer having a first low bandgap energy that bonds with the first III-nitride layer.

3. The semiconductor structure as recited in claim 2, wherein the selective photo-enhanced wet oxidation comprises photo-enhanced wet oxidation with a photonic energy between the first high bandgap energy and the first low bandgap energy.

4. The semiconductor structure as recited in claim 3, wherein the substrate structure comprises a sapphire substrate, wherein the first III-nitride layer comprises a (In/Ga)N layer, wherein the second III-nitride layer comprises a (In/Ga)N layer, and wherein the III-oxide layer comprises a (In/Ga)₂O₃ layer.

5. The semiconductor structure as recited in claim 1, further comprising:

a second substrate structure bonded with a side of the III-nitride structure that does not bond with the first substrate structure.

6. The semiconductor structure as recited in claim 5, wherein a surface of the second substrate structure comprises a metal bond layer, and wherein bonding the second substrate structure with a side of the III-nitride structure that does not bond with the first substrate structure comprises bonding the surface of the second substrate structure having the metal bond layer with the side of the III-nitride structure that does not bond with the first substrate structure.

7. The semiconductor structure as recited in claim 5, wherein the III-oxide layer is capable of being dissolved to separate the first substrate structure from the III-nitride structure.

8. The semiconductor structure as recited in claim 7, wherein separating the first substrate structure from the III-nitride structure comprises dissolving the III-oxide layer using an acidic electrolyte or a basic electrolyte.

9. The semiconductor structure as recited in claim 8, wherein the acidic electrolyte comprises H₃PO₄, and wherein the basic electrolyte comprises KOH.

10. A semiconductor structure comprising:

a light-emitting diode (LED) structure having a first substrate structure and at least a III-nitride structure having a first low bandgap energy with a first side of the III-nitride structure bonded to a first III-nitride layer having a first high bandgap energy of the first substrate structure;

a plurality of air gaps formed between the III-nitride structure and the first III-nitride layer;

a III-oxide layer formed on surfaces around the air gaps, wherein a portion of the III-nitride structure including surfaces around the air gaps is transformed into the III-oxide layer by a selective photo-enhanced wet oxidation, and the III-oxide layer is formed between an untransformed portion of the III-nitride structure and the first III-nitride layer; and

a second substrate structure bonded to a second side of the III-nitride structure.

11. The semiconductor structure as recited in claim 10, wherein the selective photo-enhanced wet oxidation comprises photo-enhanced wet oxidation with a photonic energy between the first high bandgap energy and the first low bandgap energy.

12. The semiconductor structure as recited in claim 11, wherein the first substrate structure comprises a sapphire substrate, wherein the first III-nitride layer having a first high bandgap energy comprises a (In/Ga)N layer, wherein the first side of the III-nitride structure comprises a (In/Ga)N layer, and wherein the III-oxide layer comprises a (In/Ga)₂O₃ layer.

13. The semiconductor structure as recited in claim 10, wherein the III-oxide layer is capable of being dissolved to separate the first substrate structure from the III-nitride structure.

14. The semiconductor structure as recited in claim 13, wherein dissolving the III-oxide layer comprises dissolving the III-oxide layer using an acidic electrolyte or a basic electrolyte.

15. The semiconductor structure as recited in claim 14, wherein the acidic electrolyte comprises H₃PO₄, and wherein the basic electrolyte comprises KOH.