White light emitting device

• US 7,935,974 B2
• Filed: 03/06/2009
• Issued: 05/03/2011
• Est. Priority Date: 05/31/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung LED Co., Ltd. (Samsung Electronics Co. Ltd.)
• Inventors: Koike, Masayoshi, Cho, Myong Soo, Kim, Min Ho, Min, Kyeong Ik
• Primary Examiner(s): Parker; Kenneth A
• Assistant Examiner(s): Kim; Jay C
• Application Number:
  US12/399,619
• Publication Number:
  US 20090173955A1
• Time in Patent Office: 788 Days
• Field of Search: 257/79, 257/88, 257/89, 257/90, 257/94, 257/96, 257/97, 257/E33.012, 257/E33.023, 257/E33.031, 257/E33.074, 257/E33.025, 257/E33.026, 257/E33.027, 257/E33.028, 257/E33.032, 257/E33.033, 257/E33.034
• US Class Current: 257/96
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 25/0756 Stacked arrangements of devices
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/145 with a current-blocking structure
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers

Abstract

The invention relates to a monolithic white light emitting device using wafer bonding or metal bonding. In the invention, a conductive submount substrate is provided. A first light emitter is bonded onto the conductive submount substrate by a metal layer. In the first light emitter, a p-type nitride semiconductor layer, a first active layer, an n-type nitride semiconductor layer and a conductive substrate are stacked sequentially from bottom to top. In addition, a second light emitter is formed on a partial area of the conductive substrate. In the second light emitter, a p-type AlGaInP-based semiconductor layer, an active layer and an n-type AlGaInP-based semiconductor layer are stacked sequentially from bottom to top. Further, a p-electrode is formed on an underside of the conductive submount substrate and an n-electrode is formed on a top surface of the n-type AlGaInP-based semiconductor layer.

Claims

1. A white light emitting device comprising:

a submount substrate having a p-side lead terminal and an n-side lead terminal formed thereon;

a first light emitter including a p-type nitride semiconductor layer, a first active layer, an n-type nitride semiconductor layer and an insulating substrate stacked sequentially from bottom to top, the p-type nitride semiconductor layer connected to the p-side lead terminal and the n-type nitride semiconductor layer connected to the n-side lead terminal;

a metal layer formed on a partial area of the insulating substrate;

a second light emitter formed on the metal layer, bonded to a partial area of the metal layer, the second light emitter including a p-type A1GaInP-based semiconductor layer, a second active layer and an n-type AlGaInP-based semiconductor layer stacked sequentially; and

first p- and n-electrodes connected to the p- and n-type nitride semiconductor layers of the first light emitter, respectively;

a second p-electrode connected to another area of the metal layer; and

a second n-electrode connected to the n-type AlGaInP-based semiconductor layer of the second light emitter.

2. The white light emitting device according to claim 1, wherein the submount substrate comprises a silicon substrate or a metal substrate.

3. The white light emitting device according to claim 1, wherein the metal layer comprises a high reflectivity metal selected from a group consisting of Al, Ag, Rh, Ru, Pt, Pd and alloys thereof.

4. The white light emitting device according to claim 1, wherein the insulating substrate of the first light emitter comprises a sapphire substrate.

5. The white light emitting device according to claim 1, wherein the partial area of the insulating substrate of the first light emitter is smaller than a remaining area of the insulating substrate.

6. The white light emitting device according to claim 1, wherein the insulating substrate has a rough pattern formed on an area where the second light emitter is not formed.

7. The white light emitting device according to claim 1, wherein the first active layer is adapted to generate light of a wavelength of about 450 nm to 475 nm and the second active layer is adapted to generate light of a wavelength of about 550 nm to 600 nm.

8. The white light emitting device according to claim 1, wherein the first active layer includes two active layers for generating light of a wavelength of about 450 nm to 475 nm and light of a wavelength of about 510 nm to 535 nm, respectively, and

wherein the second active layer is adapted to generate light of a wavelength of about 600 nm to 635 nm.