SiC crystals with an optimal orientation of lattice planes for fissure reduction and method of producing same

US12195878B2 · kind B2 · utility

Assignee

• SiCrystal GMBH · DE

Inventors

• Michael Vogel · Nuremberg, DE
• Erwin Schmitt · Großenseebach, DE
• Arnd-Dietrich Weber · Forchheim, DE
• Ralph-Uwe Barz · Erlangen, DE
• Dominik Bannspach · Erlangen, DE

Key dates

• Filing date: Jul 20, 2021
• Grant date: Jan 14, 2025
• Expiry date: Apr 24, 2043

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C30B33/00
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

The present invention provides monocrystalline 4H—SiC semi-finished products having a specific orientation of its crystal structure which is set such as to reduce or even eliminate the occurrence of cracks or fissures during mechanical processing, and method of producing same. The monocrystalline 4H—SiC semi-finished product, which has a longitudinal axis and an at least partially curved lateral surface parallel to said longitudinal axis, is characterized in that the crystal structure of the 4H—SiC semi-finished product is oriented with respect to the longitudinal axis such that at each position on the lateral surface of the semi-finished product there is a line segment which is intersected by at least a predetermined minimum number of parallel cleavage planes of the {1010} form per unit length, wherein the line segment is defined by a plane tangent to the lateral surface at said position.