Gallium nitride-based semiconductor light-emitting device and method of fabricatiing the same

• US 20050269583A1
• Filed: 07/27/2004
• Published: 12/08/2005
• Est. Priority Date: 06/04/2004
• Status: Abandoned Application

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Oh, Jeong Tak, Kim, Dong Joon, Lee, Kyu Han, Kim, Sun Woon, Kim, Je Won
• Application Number:
  US10/899,035
• Publication Number:
  US 20050269583A1
• Time in Patent Office: Days
• US Class Current: 257/94
• CPC Class Codes: H01L 33/02 characterised by the semiconductor bodies
• 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

Abstract

This invention pertains to a gallium nitride-based semiconductor light-emitting device, in which nano-sized, fine protrusions are formed on an upper surface of a p-type clad layer without a deterioration of crystallinity and electric conductivity to improve light extraction efficiency, and a method of fabricating the same. After a first conductive gallium nitride-based semiconductor layer and an active layer are grown on a substrate under typical growth conditions, a second conductive gallium nitride-based semiconductor layer is grown on a polarity conversion layer containing a MgN-based single crystal and formed on the active layer, so that a polarity of the second conductive gallium nitride-based semiconductor layer is converted into an N polarity, thereby roughing a surface thereof.

Claims

1. A gallium nitride-based semiconductor light-emitting device, comprising:

a substrate;

a first conductive gallium nitride-based semiconductor layer formed on the substrate;

an active layer grown on the first conductive gallium nitride-based semiconductor layer to have a Ga polarity;

a polarity conversion layer, containing a MgN-based single crystal, formed on the active layer; and

a second conductive gallium nitride-based semiconductor layer grown on the polarity conversion layer to have an N polarity.

2. The gallium nitride-based semiconductor light-emitting device as set forth in claim 1, wherein the polarity conversion layer is made of a material satisfying a compositional formula of (Al_xGa_yIn_z)Mg₃₋

(x+y+z)N₂, provided that 0≦

x,y,z≦

1 and 0<

x+y+z<

3.

3. The gallium nitride-based semiconductor light-emitting device as set forth in claim 1, wherein the polarity conversion layer is formed according to a molecular beam epitaxy (MBE) process or a metalorganic chemical vapor deposition (MOCVD) process.

4. The gallium nitride-based semiconductor light-emitting device as set forth in claim 1, wherein the polarity conversion layer is 500 Å

or less in thickness.

5. A method of fabricating a gallium nitride-based semiconductor light-emitting device, comprising:

forming a first conductive gallium nitride-based semiconductor layer on a substrate;

growing an active layer with a multi quantum well structure on the first conductive gallium nitride-based semiconductor layer so as to have a Ga polarity;

forming a polarity conversion layer on the active layer; and

growing a second conductive gallium nitride-based semiconductor layer on the polarity conversion layer so as to have an N polarity.

6. The method as set forth in claim 5, wherein the polarity conversion layer is made of a material satisfying a compositional formula of (Al_xGa_yIn_z)Mg₃₋

(x+y+z)N₂, provided that 0≦

x,y,z≦

1 and 0<

x+y+z<

3.

7. The method as set forth in claim 5, wherein the polarity conversion layer is formed according to a molecular beam epitaxy (MBE) process or a metalorganic chemical vapor deposition (MOCVD) process.

8. The method as set forth in claim 5, wherein the polarity conversion layer is formed in a thickness of 500 Å

or less.

9. The method as set forth in claim 5, further comprising etching an upper surface of the second conductive gallium nitride-based semiconductor layer according to a wet etching process.

10. The method as set forth in claim 9, wherein an etching solution is any one selected from the group consisting of a molten potassium hydroxide (KOH) solution, a phosphoric acid solution, a sulfuric acid solution, and a mixed solution of phosphoric acid and sulfuric acid.