Semiconductor light emitting device and manufacturing method of the same

• US 8,729,575 B2
• Filed: 08/23/2011
• Issued: 05/20/2014
• Est. Priority Date: 03/08/2011
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Hwang, Jongil, Hung, Hung, Hashimoto, Rei, Saito, Shinji, Tohyama, Masaki, Nunoue, Shinya, Hattori, Yasushi
• Primary Examiner(s): Menz, Laura
• Assistant Examiner(s): Malek, Maliheh
• Application Number:
  US13/215,628
• Publication Number:
  US 20120228581A1
• Time in Patent Office: 1,001 Days
• Field of Search: 257/E25.032, 257/E33.001, 257/E33.008, 257/E33.023, 257E33025-E33026, 257E33028-E33034, 257/E33.049, 257 13- 14, 257/79, 257/86, 257 88- 90, 257/94, 257 96- 97, 257/E25.019, 257/E25.02, 257/E25.028, 438/34, 438 45- 47, 438/22
• US Class Current: 257/94
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01S 2304/04 MOCVD or MOVPE
• CPC Class Codes: H01S 5/0202 Cleaving
• CPC Class Codes: H01S 5/22 having a ridge or stripe structure
• CPC Class Codes: H01S 5/3063 using Mg
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser

Abstract

The semiconductor light emitting device according to an embodiment includes an N-type nitride semiconductor layer, a nitride semiconductor active layer disposed on the N-type nitride semiconductor layer, and a P-type nitride semiconductor layer disposed on the active layer. The P-type nitride semiconductor layer includes an aluminum gallium nitride layer. The indium concentration in the aluminum gallium nitride layer is between 1E18 atoms/cm³ and 1E20 atoms/cm³ inclusive. The carbon concentration is equal to or less than 6E17 atoms/cm³. Where the magnesium concentration is denoted by X and the acceptor concentration is denoted by Y, Y>{(−5.35e19)²−(X−2.70e19)²}^1/2−4.63e19 holds.

Claims

1. A semiconductor light emitting device comprising:

an N-type nitride semiconductor layer;

an active layer of a nitride semiconductor disposed on the N-type nitride semiconductor layer; and

a P-type nitride semiconductor layer disposed on the active layer,

wherein the P-type nitride semiconductor layer includes a first aluminum gallium nitride layer, an indium concentration in the first aluminum gallium nitride layer is between 1E18 atoms/cm³ and 1E20 atoms/cm³ inclusive, a carbon concentration is equal to or less than 6E17 atoms/cm³, a magnesium concentration is between 5E18 atoms/cm³ and 3E19 atoms/cm³ inclusive, and

Y>

{(−

5.35e19)²−

(X−

2.70e19)²}^1/2−

4.63e19 holds,

where X and Y denote a magnesium concentration and an acceptor concentration respectively in the aluminum gallium nitride layer.

2. The device according to claim 1, wherein the indium concentration is between 3E18 atoms/cm³ and 3E19 atoms/cm³ inclusive, and the carbon concentration is equal to or less than 1E17 atoms/cm³.

3. The device according to claim 1, wherein the P-type nitride semiconductor layer comprises a guiding layer of P-type gallium nitride disposed on the active layer, a cladding layer disposed on the guiding layer, and a contact layer of P-type gallium nitride disposed on the cladding layer, and

the cladding layer is the aluminum gallium nitride layer.

4. The device according to claim 1, wherein the N-type nitride semiconductor layer is an N-type gallium nitride.

5. The device according to claim 1, wherein the active layer is a gallium nitride semiconductor having a multiquantum well structure.

6. The device according to claim 1, wherein a ridge stripe is provided at the P-type nitride semiconductor layer in order to form a waveguide region for laser light.

13. The device according to claim 1, wherein the P-type nitride semiconductor layer comprises a gallium nitride layer disposed on the active layer, a P-type second aluminum gallium nitride layer disposed on the gallium nitride layer, the first aluminum gallium nitride layer disposed on the second aluminum gallium nitride layer,

a thickness of the gallium nitride layer is thicker than that of the second aluminum gallium nitride layer, a thickness of the first aluminum gallium nitride layer is thicker than that of the gallium nitride layer,

a band gap of the first aluminum gallium nitride layer is larger than that of the gallium nitride layer, and a band gap of the second aluminum gallium nitride layer is larger than that of the first aluminum gallium nitride layer.

7. A method for manufacturing a semiconductor light emitting device comprising:

forming an N-type nitride semiconductor layer, an active layer of nitride semiconductor, and a P-type nitride semiconductor layer having a first aluminum gallium nitride layer including magnesium successively on a substrate by Metal Organic Chemical Vapor Deposition (MOCVD),

wherein during growth of the first aluminum gallium nitride layer, a magnesium raw material, an indium raw material, and a nitrogen gas and a hydrogen gas serving as a carrier gas are supplied into a growth atmosphere, an amount of flow of the nitrogen gas is 98.6% of total flow of the carrier gas, and a growth temperature of the first aluminum gallium nitride layer is between 800°

C. and 1000°

C. inclusive,

wherein the P-type nitride semiconductor layer comprises a gallium nitride layer disposed on the active layer, a P-type second aluminum gallium nitride layer disposed on the gallium nitride layer, the first aluminum gallium nitride layer disposed on the second aluminum gallium nitride layer,

a thickness of the gallium nitride layer is thicker than that of the second aluminum gallium nitride layer, a thickness of the first aluminum gallium nitride layer is thicker than that of the gallium nitride,

a band gap of the first aluminum gallium nitride layer is larger than that of the gallium nitride layer, and a band gap of the second aluminum gallium nitride layer is larger than that of the first aluminum gallium nitride layer.

8. The method according to claim 7, wherein the amount of the indium raw material supplied into the growth atmosphere during the growth of the first aluminum gallium nitride layer is 50% or more with respect to a summation of the amount of supply of the aluminum raw material and the amount of supply of the gallium raw material.

9. The method according to claim 7, wherein the P-type nitride semiconductor layer comprises a guiding layer of P-type gallium nitride disposed on the active layer, a cladding layer disposed on the guiding layer, and a contact layer of P-type gallium nitride disposed on the cladding layer, and

the cladding layer is the aluminum gallium nitride layer.

10. The method according to claim 7, wherein the N-type nitride semiconductor layer is an N-type gallium nitride.

11. The method according to claim 7, wherein the active layer is a gallium nitride semiconductor having a multiquantum well structure.

12. The method according to claim 7, wherein a ridge stripe is formed on the P-type nitride semiconductor layer.