Semiconductor device and method of fabricating the same

• US 9,209,358 B2
• Filed: 12/12/2012
• Issued: 12/08/2015
• Est. Priority Date: 12/14/2011
• Status: Active Grant

• Current Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Original Assignee: Seoul Viosys Co., Ltd. (Seoul Semiconductor Co., Ltd.)
• Inventors: Seo, Won Cheol, Cho, Dae Sung, Lee, Chung Hoon, Nam, Ki Bum
• Primary Examiner(s): Le, Thao P
• Application Number:
  US14/365,370
• Publication Number:
  US 20140353679A1
• Time in Patent Office: 1,091 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H01L 21/0237 Materials
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02513 Microstructure
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• 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 33/32 containing nitrogen
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/42 Transparent materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

Disclosed are a semiconductor device and a method of fabricating the same. A light emitting diode (LED) includes a conductive substrate, and a gallium nitride (GaN)-based semiconductor stack positioned on the conductive substrate. The semiconductor stack includes an active layer that is a semi-polar semiconductor layer. Accordingly, it is possible to provide an LED having improved light emitting efficiency.

Claims

1. A light-emitting diode (LED), comprising:

a conductive substrate; and

a gallium nitride (GaN)-based semiconductor stack disposed on the conductive substrate,

wherein;

the semiconductor stack comprises an active layer comprising a semi-polar semiconductor material; and

the LED is free of a growth substrate.

2. The LED of claim 1, wherein the GaN-based semiconductor stack comprises semiconductor layers disposed on a semi-polar GaN substrate.

3. The LED of claim 2, wherein the semi-polar GaN substrate comprises miscut semi-polar GaN having a principal surface inclined at an angle ranging from 15 to 85 degrees with respect to c-plane.

4. The LED of claim 3, wherein the conductive substrate is the semi-polar GaN substrate.

5. The LED of claim 1, wherein the conductive substrate comprises a metal.

6. The LED of claim 5, further comprising a reflective layer disposed between the conductive substrate and the semiconductor stack.

7. The LED of claim 1, further comprising a transparent oxide layer disposed on the semiconductor stack.

8. The LED of claim 7, wherein the transparent oxide layer comprises a first surface comprising a concavo-convex pattern.

9. The LED of claim 8, wherein the transparent oxide layer comprises indium tin oxide (ITO) or zinc oxide (ZnO).

10. The LED of claim 8, wherein an upper surface of the semiconductor stack contacting the transparent oxide layer comprises a concavo-convex pattern.

11. A method of fabricating a light-emitting diode (LED), the method comprising:

preparing a miscut semi-polar GaN substrate comprising a first surface inclined at an angle ranging from 15 to 85 degrees with respect to c-plane;

growing semi-polar GaN-based semiconductor layers on the first surface of the semi-polar GaN substrate to form a semiconductor stack;

forming a reflective layer on the semiconductor stack;

attaching a support substrate on the reflective layer; and

removing the semi-polar GaN substrate.

12. The method of claim 11, further comprising forming a transparent oxide layer on the semiconductor stack.

13. The method of claim 12, wherein the transparent oxide layer comprises a concavo-convex pattern formed in a surface thereof.

14. The method of claim 11, further comprising:

using electrochemical etching to form a nitride layer comprising a porous structure on the semi-polar GaN substrate, before forming the semiconductor stack on the semi-polar GaN substrate.

15. The method of claim 14, wherein the nitride layer separates the semi-polar GaN substrate from the semiconductor stack.

16. The method of claim 11, further comprising:

forming a concavo-convex pattern on a surface of the semiconductor stack, after the semi-polar GaN substrate is removed.

17. The method of claim 16, further comprising:

forming a transparent oxide layer on the semiconductor stack.

18. The method of claim 17, wherein a surface of the transparent oxide layer comprises a concavo-convex pattern.

19. The method of claim 17, wherein the transparent oxide layer comprises ITO or ZnO.