N-TYPE ALUMINUM NITRIDE SINGLE-CRYSTAL SUBSTRATE AND VERTICAL NITRIDE SEMICONDUCTOR DEVICE

• US 20160254391A1
• Filed: 10/15/2014
• Published: 09/01/2016
• Est. Priority Date: 10/15/2013
• Status: Active Grant

• Current Assignee: Tokuyama Corporation
• Original Assignee: Tokuyama Corporation
• Inventors: Obata, Toshiyuki, Kinoshita, Toru, Nagashima, Toru
• Granted Patent: US 9,748,410 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C30B 25/20 the substrate being of the same materials as the epitaxial layer
• CPC Class Codes: C30B 29/403 AIII-nitrides
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02576 N-type
• CPC Class Codes: H01L 21/02598 monocrystalline
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 29/04 characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes characterised by physical imperfections H01L29/30
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 29/205 in different semiconductor regions , e.g. heterojunctions
• CPC Class Codes: H01L 29/207 further characterised by the doping material H01L29/2006 takes precedence
• CPC Class Codes: H01L 29/32 the imperfections being within the semiconductor body
• CPC Class Codes: H01L 29/36 characterised by the concentration or distribution of impurities in the bulk material within semiconductor regions H01L29/06
• CPC Class Codes: H01L 29/47 Schottky barrier electrodes H01L29/435 takes precedence
• CPC Class Codes: H01L 29/66143 Schottky diodes
• CPC Class Codes: H01L 29/872 Schottky diodes

Abstract

A vertical nitride semiconductor device includes an n-type aluminum nitride single-crystal substrate having an Si content of 3×10¹⁷ to 1×10²⁰ cm⁻³ and a dislocation density of 10⁶ cm⁻² or less. An ohmic electrode layer is formed on an N-polarity side of the n-type aluminum nitride single-crystal substrate.

Claims

1. A n-type aluminum nitride single crystal substrate wherein a Si content is 3×

10¹⁷ to 1×

10²⁰ cm<sup>−

3</sup>, a dislocation density is 10⁶ cm<sup>−

2</sup> or less, and a thickness is 50 to 500 μ

m.

2. A vertical nitride semiconductor device comprising electrode layers on top and bottom of principal planes of the n-type aluminum nitride single crystal substrate as set forth in claim 1.

3. A vertical Schottky barrier diode comprising an ohmic electrode layer on one principal plane side and a Schottky electrode layer on the other principal plane of the n-type aluminum nitride single crystal substrate in the vertical nitride semiconductor device as set forth in claim 2.

4. A laminated body stacked with a layer represented by Al_XGa_1-XN, wherein X is a rational number satisfying 0.3≦

X≦

0.8 and having a Si content of 1×

10¹⁸ to 5×

10¹⁹ cm<sup>−

3</sup>, on at least one principal plane of the n-type aluminum nitride single crystal substrate as set forth in claim 1.

5. A vertical nitride semiconductor device comprising electrode layers on top and bottom of principal planes of the layered body as set forth in claim 4.

6. The vertical nitride semiconductor device as set forth in claim 5 wherein one electrode layer on the layer represented by Al_XGa_1-XN, wherein X is a rational number satisfying 0.3≦

X≦

0.8 is an ohmic electrode layer.

7. A vertical Schottky barrier diode wherein one electrode layer on the n-type aluminum nitride single crystal substrate in the vertical nitride semiconductor device as set forth in claim 6 is a Schottky electrode layer.

8. The vertical Schottky barrier diode as set forth in claim 3 wherein an electric current density is 10⁻

6 Acm<sup>−

2</sup> or less when a reverse voltage is 100V.

9. A production method of the n-type aluminum nitride single crystal substrate as set forth in claim 1 comprising:

forming a n-type aluminum nitride single crystal layer having a Si content of 1×

10¹⁷ to 1×

10²⁰ cm<sup>−

3</sup> and a dislocation density of 10⁶ cm<sup>−

2</sup> or less on an aluminum nitride single crystal seed substrate having a dislocation density of 10⁴ cm<sup>−

2</sup> or less, and

separating said aluminum nitride single crystal seed substrate and said n-type aluminum nitride single crystal layer to thereby obtaining the n-type aluminum single crystal substrate from said n-type aluminum nitride single crystal layer.

10. The vertical Schottky barrier diode as set forth in claim 7 wherein an electric current density is 10⁻

6 Acm<sup>−

2</sup> or less when a reverse voltage is 100V.