Method for manufacturing nitride crystal substrate and substrate for crystal growth

Patent metadata

Field	Value
Publication number	US-2017191186-A1
Application number	US-201715398319-A
Country	US
Kind code	A1
Filing date	Jan 4, 2017
Priority date	Jan 5, 2016
Publication date	Jul 6, 2017
Grant date	—

Abstract

There is provided a method for manufacturing a nitride crystal substrate, including: arranging a plurality of seed crystal substrates made of a nitride crystal in a planar appearance, so that their main surfaces are parallel to each other and their lateral surfaces are in contact with each other; growing a first crystal film using a vapor-phase growth method on a surface of the plurality of seed crystal substrates arranged in the planar appearance, and preparing a combined substrate formed by combining the adjacent seed crystal substrates each other by the first crystal film; growing a second crystal film using a liquid-phase growth method on a main surface of the combined substrate so as to be embedded in a groove that exists at a combined part of the seed crystal substrates, and preparing a substrate for crystal growth having a smoothened main surface; and growing a third crystal film using the vapor-phase growth method, on the smoothed main surface of the substrate for crystal growth.

First claim

1 . A method for manufacturing a nitride crystal substrate, comprising:
arranging a plurality of seed crystal substrates made of a nitride crystal in a planar appearance, so that their main surfaces are parallel to each other and their lateral surfaces are in contact with each other; growing a first crystal film using a vapor-phase growth method on a surface of the plurality of seed crystal substrates arranged in the planar appearance, and preparing a combined substrate formed by combining the adjacent seed crystal substrates each other by the first crystal film; growing a second crystal film using a liquid-phase growth method on a main surface of the combined substrate so as to be embedded in a groove that exists at a combined part of the seed crystal substrates, and preparing a substrate for crystal growth having a smoothened main surface; and growing a third crystal film using the vapor-phase growth method, on the smoothed main surface of the substrate for crystal growth.

2 . The method for manufacturing a nitride crystal substrate according to claim 1 , wherein the seed crystal substrates are made of GaN crystals, the main surface of the seed crystal substrates is a c-plane, and all lateral surfaces of the seed crystal substrates in contact with lateral surfaces of other seed crystal substrates are a-planes.

3 . The method for manufacturing a nitride crystal substrate according to claim 1 , wherein preparing the combined substrate is performed in a state of holding the plurality of seed crystal substrates on a holding plate, a thickness of the first crystal film is set to a minimum necessary thickness for maintaining a combined state of the adjacent seed crystal substrates even when the combined substrate is removed from the holding plate.

4 . The method for manufacturing a nitride crystal substrate according to claim 3 , wherein the thickness of the first crystal film is set to a minimum necessary thickness for maintaining a combined state of the adjacent seed crystal substrates, even when the combined substrate removed from the holding plate is immersed in a raw material melt or a raw material solution when preparing the substrate for crystal growth.

5 . The method for manufacturing a nitride crystal substrate according to claim 1 , wherein when an outer diameter of the combined substrate is set to D cm, the thickness of the first crystal film is set in a range of 30D μm or more and 100D μm or less.

6 . The method for manufacturing a nitride crystal substrate according to claim 1 , wherein a thickness of the second crystal film is set to a minimum necessary thickness for smoothing the main surface of the substrate for crystal growth by embedding the second crystal film in the groove.

7 . The method for manufacturing a nitride crystal substrate according to claim 1 , wherein the second crystal film is formed on the surface of the combined substrate on the side where the first crystal film is formed.

8 . The method for manufacturing a nitride crystal substrate according to claim 1 , wherein the first crystal film and the third crystal film are grown using a vapor-phase growth method which is Hydride Vapor-phase Epitaxy method, and different processing conditions are set between when growing the first crystal film, and when growing the third crystal film.

9 . A crystal growth substrate, comprising:
a plurality of seed crystal substrates made of a nitride crystal, arranged in a planar appearance, so that their main surfaces are parallel to each other and their lateral surfaces are in contact with each other; a first crystal film formed using a vapor-phase growth method on a surface of the plurality of seed crystal substrates arranged in the planar appearance, and configured to combine the adjacent seed crystal substrates each other; and a second crystal film formed using a liquid-phase growth method on a main surface of the plurality of seed crystal substrates on which the first crystal film is formed, and having a smoothened main surface by being embedded in a groove that exist at a combined part of the seed crystal substrates.

Assignees

• Univ Osaka
• Sciocs Co Ltd
• Sumitomo Chemical Co

Inventors

• Mori Yusuke
• Yoshimura Masashi
• Imade Mamoru
• Imanishi Masayuki
• Shibata Masatomo
• Yoshida Takehiro

Classifications

• H10P90/00

  Preparation of wafers not covered by a single main group of this subclass, e.g. wafer reinforcement · CPC title

• H10P14/2924

  Structures · CPC title

• H10P14/2908

  Nitrides · CPC title

• H10P14/263

  using melted materials · CPC title

• H10P14/24

  using chemical vapour deposition [CVD] · CPC title