# US 2013/0157445 A1 · POLYCRYSTALLINE ALUMINUM NITRIDE BASE MATERIAL FOR CRYSTAL GROWTH OF GaN-BASE SEMICONDUCTOR AND METHOD FOR MANUFACTURING GaN-BASE SEMICONDUCTOR USING THE SAME

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- Number: US 2013/0157445 A1
- Document ID: US20130157445A1
- Status: Published application
- Kind: A1
- Application number: 13/806,320
- Filed: 2011-08-03
- Published: 2013-06-20
- Earliest claimed: 2010-08-10
- Inventors: Kimiya Miyashita; Michiyasu Komatsu; Katsuyuki Aoki; Kai Funaki
- Web page: https://patentgrep.com/patent/US20130157445A1

## CPC

- H10P 14/2908: {Nitrides}
- C04B 35/581: based on aluminium nitride
- C04B 41/009: {characterised by the material treated}
- C04B 41/5062: {Borides, Nitrides or Silicides}
- C04B 41/87: Ceramics
- C30B 25/18: characterised by the substrate
- C30B 29/403: {AIII-nitrides}
- C30B 29/406: {Gallium nitride}
- H10P 14/3416: {Nitrides}
- C04B 2111/00844: {for electronic applications}
- C04B 2235/3217: Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
- C04B 2235/3222: Aluminates other than alumino-silicates, e.g. spinel (MgAl2O4)
- C04B 2235/3224: Rare earth oxide or oxide forming salts thereof, e.g. scandium oxide
- C04B 2235/3225: Yttrium oxide or oxide-forming salts thereof
- C04B 2235/3852: Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
- C04B 2235/3886: Refractory metal nitrides, e.g. vanadium nitride, tungsten nitride
- C04B 2235/5436: micrometer sized, i.e. from 1 to 100 micron
- C04B 2235/5445: submicron sized, i.e. from 0,1 to 1 micron
- C04B 2235/80: Phases present in the sintered or melt-cast ceramic products other than the main phase
- C04B 2235/9607: Thermal properties, e.g. thermal expansion coefficient
- Y10T 428/21: Circular sheet or circular blank
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

There is provided a polycrystalline aluminum nitride base material having a linear expansion coefficient similar to GaN. The polycrystalline aluminum nitride base material as a substrate material for crystal growth of GaN-base semiconductors has a mean linear expansion coefficient of 4.9×10−6/K to 6.1×10−6/K between 20° C. and 600° C. and 5.5×10−6/K to 6.6×10−6/K between 20° C. and 1100° C.

## Claims

### Claim 1

A polycrystalline aluminium nitride base material for use as a substrate material for crystal growth of GaN-base semiconductors, the polycrystalline aluminium nitride base material having a mean linear expansion coefficient of 4.9×10−6/K to 6.1×10−6/K between 20° C. and 600° C. and 5.5×10−6/K to 6.6×10−6/K between 20° C. and 1100° C.

### Claim 2 (depends on 1)

The polycrystalline aluminum nitride base material according to claim 1, which comprises an aluminum nitride crystal and a grain boundary phase, the content of the aluminum nitride crystal being 56.2% to 93.9% in terms of volume fraction.

### Claim 3 (depends on 1)

The polycrystalline aluminum nitride base material according to claim 1, wherein the grain boundary phase comprises a composite oxide composed of at least one material selected from the group consisting of Ca (calcium), Y (yttrium), La (lanthanum), Ce (cerium), Nd (neodymium), Pr (praseodymium), Eu (europium), Gd (gadolinium), Dy (dysprosium), Ho (holmium), Er (erbium), Yb (ytterbium), and Lu (lutetium) and aluminum.

### Claim 4 (depends on 1)

The polycrystalline aluminum nitride base material according to claim 1, wherein the grain boundary phase contains titanium nitride (TiN).

### Claim 5 (depends on 1)

The polycrystalline aluminum nitride base material according to claim 1, wherein crystal grains of the aluminum nitride have a mean diameter of not more than 7 μm.

### Claim 6 (depends on 1)

The polycrystalline aluminum nitride base material according to claim 1, which has a thermal conductivity of not less than 46 W/m·K.

### Claim 7 (depends on 1)

The polycrystalline aluminum nitride base material according to claim 1, which has a diameter of not less than 50 mm.

### Claim 8 (depends on 1)

The polycrystalline aluminum nitride base material according to claim 1, which has a surface roughness (Ra) of not more than 0.2 μm and a thickness of not more than 3 mm.

### Claim 9 (depends on 1)

A method for manufacturing a GaN-base semiconductor, the method comprising: growing a GaN-base semiconductor crystal using a polycrystalline aluminum nitride base material according to claim 1.

### Claim 10 (depends on 9)

The method for manufacturing a GaN-base semiconductor according to claim 9, wherein the GaN-base semiconductor crystal is grown through a buffer layer.

### Claim 11 (depends on 9)

The method for manufacturing a GaN-base semiconductor according to claim 9, wherein the GaN-base semiconductor is at least one semiconductor selected from the group consisting of GaN, InGaN, AlGaN, and InAlGaN.