A kind of silicon carbide crystal, the seed crystal used and the preparation method of the seed crystal

Abstract

The present application discloses a silicon carbide crystal, a seed crystal used therefor and a method for preparing the seed crystal, belonging to the technical field of semiconductor materials. The silicon carbide seed crystal includes a first surface and a second surface opposite to the first surface, the first surface and / or the second surface has a plurality of atomic steps, and the width of the atomic steps is 50 ~1000 nm, the height of the atomic steps is 0.02-0.5 nm; the width difference between a plurality of the atomic steps is not more than 10 nm; and / or the height difference between the multiple atomic steps is not more than 0.01 nm. The atomic steps of the silicon carbide seed crystal are uniformly arranged, and the size of each step is uniform, which lays a foundation for subsequent growth to obtain ultra-high-quality crystals.

Description

technical field [0001] The present application relates to a silicon carbide crystal, a seed crystal used therefor and a method for preparing the seed crystal, and belongs to the technical field of semiconductor materials. Background technique [0002] As one of the important third-generation semiconductor materials, SiC crystal has excellent performance in high temperature, high frequency, high power, radiation resistance, etc. SiC-based devices have been widely used in military, civil, aerospace and other fields. Application is a key area of ​​scientific and technological research in various countries. [0003] At present, the most widely used method for growing silicon carbide crystals is the physical vapor transport method, followed by the liquid phase method and the chemical vapor transport method. When the above-mentioned growth method is used to prepare a high-quality silicon carbide substrate, a high-quality silicon carbide seed crystal is indispensable, that is, a s...

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Problems solved by technology

However, due to the unbalanced ratio of growth materials in the above-mentioned seed crystal, it is difficult to obtain high-quality seed crystal wafers without macroscopic defects, and the efficiency is low. Each crystal ingot can only obtain one seed crystal; Optimizing the seed crystal growth on the a-plane, the cycle is very long and there are too many coupling factors in the growth process, so it is difficult to obtain high-quality seed crystals

[0005] In addition, due to the uncontrollable atomic step density of traditional seed crystals, defects such as polymorphism and dislocations are prone to occur during the growth process, and it is difficult to guarantee the quality of the subsequent growth of silicon carbide crystals

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