GALLIUM NITRIDE-BASED SEMICONDUCTOR ELEMENT, OPTICAL DEVICE USING THE SAME, AND IMAGE DISPLAY APPARATUS USING OPTICAL DEVICE

• US 20090008648A1
• Filed: 06/12/2008
• Published: 01/08/2009
• Est. Priority Date: 07/03/2007
• Status: Active Grant

• Current Assignee: Sony Semiconductor Solutions Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Okuyama, Hiroyuki, Biwa, Goshi, Nishinaka, Ippei
• Granted Patent: US 8,946,764 B2
• Time in Patent Office: Days
• US Class Current: 257/76
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 27/1446 in a repetitive configuration
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 31/0304 including, apart from doping materials or other impurities, only AIIIBV compounds
• CPC Class Codes: H01L 33/025 Physical imperfections, e.g. particular concentration or distribution of impurities
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A GaN-based semiconductor element which can suppress a leakage current generated during reverse bias application, an optical device using the same, and an image display apparatus using the optical device are provided. The GaN-based semiconductor element has a first GaN-based compound layer including an n-type conductive layer; a second GaN-based compound layer including a p-type conductive layer; and an active layer provided between the first GaN-based compound layer and the second GaN-based compound layer. In this GaN-based semiconductor element, the first GaN-based compound layer includes an underlayer having an n-type impurity concentration in the range of 3×10¹⁸ to 3×10¹⁹/cm³, and when a reverse bias of 5 V is applied, a leakage current density, which is the density of a current flowing per unit area of the active layer, is 2×10⁻⁵ A/cm² or less.

Claims

1. A gallium nitride-based semiconductor element comprising:

a first GaN-based compound layer including an n-type conductive layer;

a second GaN-based compound layer including a p-type conductive layer; and

an active layer provided between the first GaN-based compound layer and the second GaN-based compound layer,

wherein the first GaN-based compound layer includes an underlayer having an n-type impurity concentration in the range of 3×

10¹⁸ to 3×

10¹⁹/cm³, and when a reverse bias of 5 V is applied, a leakage current density, which is the density of a current flowing per unit area of the active layer, is 2×

10<sup>−

5</sup> A/cm² or less.

2. The gallium nitride-based semiconductor element according to claim 1, wherein the n-type impurity concentration of the underlayer is 4×

10¹⁸/cm³ or more, and the leakage current density is 8×

10<sup>−

6</sup> A/cm² or less.

3. The gallium nitride-based semiconductor element according to claim 1, wherein the n-type impurity concentration of the underlayer is 8×

10¹⁸/cm³ or more, and the leakage current density is 1+10<sup>−

6</sup> A/cm² or less.

4. The gallium nitride-based semiconductor element according to claim 1, wherein the n-type impurity concentration of the underlayer is 1×

10¹⁹/cm³ or more, and the leakage current density is 6×

10<sup>−

7</sup> A/cm² or less.

5. The gallium nitride-based semiconductor element according to claim 1, wherein the underlayer and the active layer each include a GaN-based compound containing In, the In composition ratio of the GaN-based compound forming the underlayer is 0.005 or more and is lower than that of the GaN-based compound forming the active layer.

6. The gallium nitride-based semiconductor element according to claim 1, wherein the underlayer has a thickness in the range of 5 nm to 5 μ

m.

7. The gallium nitride-based semiconductor element according to claim 1, wherein the underlayer has a thickness in the range of 20 nm to 1 μ

m.

8. The gallium nitride-based semiconductor element according to claim 1, wherein the second GaN-based compound layer includes a GaN layer doped with a p-type impurity and having a thickness of 100 nm or more.

9. The gallium nitride-based semiconductor element according to claim 1, wherein the gallium nitride-based semiconductor element is a light-emitting element.

10. An optical device comprising:

a plurality of gallium nitride-based semiconductor elements, each of which is the gallium nitride-based semiconductor element according to claim 1, arranged in a two-dimensional matrix,

wherein first electrodes of the gallium nitride-based semiconductor elements disposed along lines in a first direction are connected to common wires of the respective lines in the first direction, and

second electrodes of the gallium nitride-based semiconductor elements disposed along lines in a second direction are connected to common wires of the respective lines in the second direction.

11. An image display apparatus comprising:

a pixel portion including the optical device according to claim 10,

wherein the gallium nitride-based semiconductor elements are passive matrix driven.