Denso Corporation

Central Research Institute of Electric Power Industry

2)Denso Corporation

1)Mirise Technologies Corporation

3)Toyota Jidosha Kabushiki Kaisha

Norihiro Hoshino

Hidekazu Tsuchida

Isaho Kamata

Yuichiro Tokuda

Takeshi Okamoto

Hideyuki Uehigashi

Akiyoshi Horiai

Kiyoshi Betsuyaku

Takahiro Kanda

A silicon carbide ingot having micropipes in a seed crystal closed and being reduced in the gathering of screw dislocations, a method for manufacturing the silicon carbide ingot, and a method for manufacturing a silicon carbide wafer are provided. The silicon carbide ingot includes a seed crystal composed of a silicon carbide single crystal and having micropipes being hollow defects; a buffer layer provided on the seed crystal and composed of silicon carbide; and a bulk crystal growth layer provided on the buffer layer and composed of silicon carbide. The buffer layer and the bulk crystal growth layer have a plurality of screw dislocations continuous with the micropipes closed with the buffer layer, and the plurality of screw dislocations having the micropipe in common in the bulk crystal growth layer are 150 um or more apart from each other.

Silicon carbide ingot including screw dislocations

A method and an apparatus for manufacturing a silicon carbide single crystal, and a silicon carbide single crystal ingot, obtaining a silicon carbide single crystal reduced in defects such as threading dislocations, are provided. The method manufactures a silicon carbide single crystal by supplying a raw material gas into a reaction vessel with a seed substrate, and heats the interior to grow a silicon carbide single crystal on the surface of the seed substrate. The method includes growing the silicon carbide single crystal on the seed substrate surface, while controlling the temperature, to perform pair annihilation of threading dislocations or synthesis of the threading dislocations; and a second step of maintaining the temperature inside the reaction vessel in the state of the first predetermined temperature after execution of the first step, to bring the leading ends of the threading dislocations close to the surface of the seed substrate.

Method and apparatus for manufacturing silicon carbide single crystal, and silicon carbide single crystal ingot

In a silicon carbide single crystal wafer, a dislocation density contained therein is 3500 dislocations/cmor less, and a difference of the dislocation density among a wafer central part, a wafer peripheral part and a wafer intermediate part is less than 50% of an average value thereof.

Silicon carbide single crystal wafer, and methods for manufacturing silicon carbide single crystal ingot and the silicon carbide single crystal wafer

A raw material gas is supplied to a space in which a silicon carbide seed crystal is placed. A silicon carbide single crystal is grown on the seed crystal by keeping a monosilane partial pressure at 4 kPa or more and heating the space to a temperature of 2400° C. to 2700° C. The temperature of the space and supply of the raw material gas are controlled such that a temperature gradient of a growth crystal surface of the silicon carbide single crystal in a radial direction is 0.1° C./mm or less, and a radius of curvature of the growth crystal surface is 4.5 m or more, thereby producing a silicon carbide single crystal ingot having a growth length of 3 mm or more and an internal stress of 10 MPa or less. The ingot is then cut into a silicon carbide single crystal wafer.

Methods for manufacturing silicon carbide single crystal ingot and silicon carbide single crystal wafer

A silicon carbide single crystal contains a heavy metal element having a specific gravity higher than a specific gravity of iron. An addition density of the heavy metal element at least in an outer peripheral portion of the silicon carbide single crystal is set to 1×10cmor more.

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Tokyo, Japan

Norihiro Hoshino