Sumitomo Electric Industries, Limited

Shunsaku Ueta

Tsutomu Hori

Kyoko Okita

Akira Matsushima

Naoki Kaji

Shin Harada

Takashi Sakurada

Eiryo Takasuka

Sho Sasaki

Hidehiko Mishima

Hirokazu Eguchi

Shinsuke Fujiwara

Taro Nishiguchi

Tsubasa Honke

Naoki Ooi

Hiroki Takaoka

A middle cross-section includes a dense region in which an area density of threading screw dislocations is 2 or more times an overall average area density. An area of the dense region is 10% or less of an area of the middle cross-section. A line density of a stacking fault in each of a first and a second cross-sections is 1/cm or less, the first cross-section being separated from a first boundary toward a second boundary by a distance of 0.1 times a distance between the first and second boundaries, the second cross-section being a cross-section separated from the second boundary toward the first boundary by a distance of 0.1 times the distance between the first and second boundaries. The middle cross-section includes a sparse density region in which an area density of threading screw dislocations is lower than half the overall average area density.

Silicon carbide single crystal and silicon carbide substrate

A silicon carbide substrate includes a dopant. The silicon carbide substrate has, on an off-downstream side with respect to a center of the silicon carbide substrate in plan view, a portion having a resistivity lower than a resistivity at the center of the silicon carbide substrate in plan view. A value obtained by dividing a difference between the resistivity of the silicon carbide substrate at the center of the silicon carbide substrate in plan view and a minimum resistivity of the silicon carbide substrate on the off-downstream side with respect to the center of the silicon carbide substrate in plan view by the resistivity of the silicon carbide substrate at the center of the silicon carbide substrate in plan view is 0.015 or less. The resistivity of the silicon carbide substrate increases from a position at which the silicon carbide substrate has the minimum resistivity toward the off-downstream side.

Silicon carbide substrate

A silicon carbide substrate has a first main surface and a second main surface opposite to the first main surface. The silicon carbide substrate includes screw dislocations and pits having a maximum diameter of 1 μm or more and 10 μm or less in a direction parallel to the first main surface. When the screw dislocations and the pits are observed in the first main surface, a percentage obtained by dividing a number of the pits by a number of the screw dislocations is 1% or less. A concentration of magnesium in the first main surface is less than 1×10atoms/cm.

Silicon carbide substrate and method of manufacturing silicon carbide substrate

In a case where a detector is positioned in a [11-20] direction, and where a first measurement region including a center of a main surface is irradiated with an X ray in a direction within &#xb1;15&#xb0; relative to a [&#x2212;1-120] direction, a ratio of a maximum intensity of a first intensity profile is more than or equal to 1500. In a case where the detector is positioned in a direction parallel to a [&#x2212;1100] direction, and where the first measurement region is irradiated with an X ray in a direction within &#xb1;6&#xb0; relative to a [1-100] direction, a ratio of a maximum intensity of a second intensity profile is more than or equal to 1500. An absolute value of a difference between maximum value and minimum value of energy at which the first intensity profile indicates a maximum value is less than or equal to 0.06 keV.

Silicon carbide single crystal substrate

A silicon carbide substrate whose majority carrier density is 1&#xd7;10cmor greater is such that a standard deviation of minority carrier lifetime as obtained by &#x3bc;-PCD analysis is 0.7 ns or less in an area other than an area within a distance of 5 mm from an outer perimeter of a main surface.

A silicon carbide substrate includes a carbon-surface-side principal surface and a silicon-surface-side principal surface. The silicon carbide substrate has a diameter of 100 mm or greater and a thickness of 300 &#x3bc;m or greater. An off angle of the carbon-surface-side principal surface and the silicon-surface-side principal surface relative to a {0001} plane is smaller than or equal to 4&#xb0;. A nitrogen concentration in the carbon-surface-side principal surface is higher than a nitrogen concentration in the silicon-surface-side principal surface, and a difference in Raman peak shift between the carbon-surface-side principal surface and the silicon-surface-side principal surface is smaller than or equal to 0.2 cm.

Provided is a method for manufacturing a silicon carbide single crystal capable of easily separating a silicon carbide single crystal from a pedestal. The method includes the step of fixing a seed substrate to a pedestal with a stress buffer layer being interposed therebetween, the step of growing a silicon carbide single crystal on the seed substrate, the step of separating the silicon carbide single crystal from the pedestal at the stress buffer layer, and the step of removing a residue of the stress buffer layer adhering to the silicon carbide single crystal subjected to the step of separating.

Method for manufacturing silicon carbide single crystal

A method for producing a single crystal includes a step of placing a source material powder and a seed crystal within a crucible, and a step of growing a single crystal on the seed crystal. The crucible includes a peripheral wall part and a bottom part and a lid part that are connected to the peripheral wall part to close the openings of the peripheral wall part, the lid part having a holder that holds the seed crystal. The bottom part has a connection region connected to the peripheral wall part and a thick region that is thicker than the connection region and that surrounds a central axis passing through a center of gravity of orthogonal projection of the bottom part, the orthogonal projection being formed on a plane perpendicular to a growth direction of the single crystal, the central axis extending in the growth direction of the single crystal.

Method for producing single crystal

A method for producing a single crystal includes a step of placing a source material powder and a seed crystal within a crucible; and a step of growing a single crystal on the seed crystal. The crucible includes a peripheral wall part and a bottom part and a lid part that are connected to the peripheral wall part to close the openings of the peripheral wall part. In the step of growing the single crystal on the seed crystal, the crucible is disposed on a spacer so as to form a space starting directly below an outer surface of the bottom part, and the peripheral wall part and an auxiliary heating member that is placed so as to face the outer surface of the bottom part with the space therebetween are heated by induction heating to sublime the source material powder to cause recrystallization on the seed crystal.

A method of manufacturing a silicon carbide substrate has the following steps. A silicon carbide source material is partially sublimated. After partially sublimating the silicon carbide source material, a seed substrate having a main surface is placed in a growth container. By sublimating the remainder of the silicon carbide source material in the growth container, a silicon carbide crystal grows on the main surface of the seed substrate. In this way, an increase of dislocations in the main surface of the seed substrate can be suppressed, thereby providing a method of manufacturing a silicon carbide substrate having few dislocations.

Growing community of inventors

Itami, Japan

Shunsaku Ueta