Sic crystalline substrates with an optimal orientation of lattice planes for fissure reduction and method of producing same

Abstract

The present invention provides monocrystalline 4H-SiC substrates 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 substrate, 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 substrate 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.

Description

technical field [0001] The present invention relates to a bulk silicon carbide (SiC) single crystal having a specific crystal structure orientation for reducing or eliminating the occurrence of cracks or fissures during machining, and a method of producing a single crystal SiC substrate having such an orientation. Background technique [0002] Silicon carbide (SiC) substrates are commonly used to produce electronic components with a wide range of applications, such as power electronics, radio frequency and optoelectronic applications. They are usually produced from bulk SiC single crystals, which can be grown using standard methods such as physical vapor deposition (PVT) and suitable source materials. SiC substrates are then produced from the grown crystals by dicing the wafer using a wire saw and then refining the wafer surface in a multi-stage polishing step. In the following epitaxial process, a thin single-crystal layer of semiconductor material (eg SiC, GaN (gallium ni...

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Problems solved by technology

[0015] However, no solution is disclosed for reducing the occurrence of cracks, which may even appear on low or unstressed SiC semi-finished products or SiC substrates during machining, depending on the applied mechanical force.

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