Silicon carbide single crystal ingot, substrate and preparation method thereof

Abstract

The invention relates to a silicon carbide single crystal ingot, a substrate and a preparation method thereof, and belongs to the field of semiconductor materials. The silicon carbide substrate contains a nitrogen element, the silicon carbide substrate has no more than 50 hexagonal color spots, and the edges forming the hexagonal color spots are perpendicular to the <10-10> direction. The edges of the hexagonal color spots comprise inner side edges and outer side edges, the inner side edges defines a hexagonal area, cavities are formed between the inner side edges and the outer side edges, and the centers of not smaller than 80% of the cavities are located on one side of the central axis between the inner side edges and the outer side edges. The invention provides the nitrogen-containing silicon carbide substrate with novel defects, namely few hexagonal color spots and cavity defects, the resistivity of the silicon carbide substrate is uniform, and a semiconductor device prepared from the silicon carbide substrate is excellent in electrical performance; and the performance of the silicon carbide substrate such as breakdown field intensity is excellent, and the number of cavities generated by extension of the manufactured device is extremely small.

Description

technical field [0001] The application relates to a silicon carbide single crystal ingot, a substrate and a preparation method thereof, belonging to the field of semiconductor materials. Background technique [0002] Silicon carbide single crystal is one of the most important third-generation semiconductor materials. It is widely used in power electronics, RF devices, optoelectronic devices and other fields. At present, the main preparation method of silicon carbide single crystal is the physical vapor transport (PVT) method, which is also the most successful method for growing large-diameter SiC crystals so far. It mainly transports the gas phase source generated by the sublimation of the silicon carbide raw material at high temperature to the seed crystal to recrystallize and grow SiC crystal. [0003] Currently mature SiC devices include: silicon carbide Schottky diodes, which mainly use junction barrier Schottky diodes or hybrid p-n Schottky diode structures; silicon c...

AI Technical Summary

Problems solved by technology

However, the quality requirements for silicon carbide single crystal growth are high, and the influencing factors are complex. The understanding of defects in silicon carbide single crystals is still in an incomplete stage, and the quality of silicon carbide single crystals is important to the manufactured devices and needs to be continuously improved. The quality of SiC substrates to ensure the quality of fabricated devices

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