Silicon carbide crystal, seed crystal used by silicon carbide crystal and preparation method of seed crystal

Abstract

The invention discloses a silicon carbide crystal, a seed crystal used by the silicon carbide crystal and a preparation method of the seed crystal, and belongs to the technical field of semiconductor materials. The silicon carbide seed crystal comprises a first surface and a second surface opposite to the first surface, wherein the first surface and / or the second surface are / is provided with a plurality of atomic steps, 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 the plurality of atomic steps is not greater than 10 nm, and / or the height difference between the plurality of atomic steps is not greater than 0.01 nm. According to the invention, the atomic steps of the silicon carbide seed crystal are uniformly arranged, and the size of each step is uniform, so that a foundation is laid for obtaining ultrahigh-quality crystals through subsequent growth.

Description

technical field [0001] The present application relates to a silicon carbide crystal, a seed crystal used therein and a method for preparing the seed crystal, belonging to the technical field of semiconductor materials. Background technique [0002] As one of the important third-generation semiconductor materials, silicon carbide crystals have excellent performance in high temperature, high frequency, high power, and radiation resistance. Silicon carbide-based devices have been widely used in military, civil, aerospace and other fields. Application is the key field of science and technology 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 methods are used to prepare high-quality silicon carbide substrates, high-quality silicon carbide seed crystals are inseparab...

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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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