Light generating semiconductor device and method of making the same

• US 7,550,776 B2
• Filed: 02/21/2008
• Issued: 06/23/2009
• Est. Priority Date: 08/08/2003
• Status: Active Grant

• Current Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Original Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Inventors: Akita, Katsushi
• Primary Examiner(s): TRAN, MINH LOAN
• Application Number:
  US12/071,440
• Publication Number:
  US 20080149954A1
• Time in Patent Office: 488 Days
• Field of Search: 257/96, 257/98, 257/103, 257/E33.034, 257/E33.068
• US Class Current: 257/96
• 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: Y10S 438/977 Thinning or removal of substrate

Abstract

In a method of making a semiconductor light generating device, a GaN-based semiconductor portion is formed on a GaN or AlGaN substrate. The GaN-based semiconductor portion includes a light generating film. An electrode film is formed on the GaN-based semiconductor film. A conductive substrate is bonded to a surface of the electrode film using a conductive adhesive. After bonding the conductive substrate, the GaN or AlGaN substrate is separated from the GaN-based semiconductor portion to form the semiconductor light generating device.

Claims

1. A semiconductor light generating device comprising:

a GaN-based semiconductor portion including a light generating layer, the light generating layer having a density of threading dislocations smaller than 1×

10⁷cm<sup>−

2</sup>;

an electrode provided on the GaN-based semiconductor portion;

a conductive substrate bonded to a surface of the electrode by a conductive adhesive.

2. The semiconductor light generating device according to claim 1, wherein the light generating layer is made of a GaN-based semiconductor having a bandgap energy greater than GaN semiconductor.

3. The semiconductor light generating device according to claim 1, wherein the light generating layer is made of a semiconductor material of a bandgap energy greater than Al_xGa₁₋

xN (0<

x≦

1).

4. The semiconductor light generating device according to claim 1, wherein the electrode is made of material having a reflectivity greater than the conductive substrate at a peak wavelength of light from the light generating layer.

5. The semiconductor light generating device according to claim 1, wherein the light generating layer is made of a nitride-based compound semiconductor containing aluminum.