Silicon carbide crystal growth method and device

Abstract

The invention provides a silicon carbide crystal growth method and device. The method comprises the steps: (1) an assembly stage; (2) a sublimation stage: controlling a plurality of separation platesto rotate until there is no gap between the plurality of separation plates and between the separation plates and the inner wall of a cavity, separating a first crucible from a second crucible, and heating to sublimate a silicon carbide raw material; and (3) a crystal growth stage: controlling the plurality of separation plates to rotate until a gap exists between the plurality of separation platesand / or between the separation plate and the inner wall of the cavity, communicating the second crucible with the first crucible through the gap, and heating to enable the silicon carbide raw materialatmosphere to pass through the gap to be transmitted to the seed crystal for crystal growth. By controlling rotation of the multiple separation plates, the first crucible and the second crucible areseparated, the sublimated atmosphere of the silicon carbide raw material cannot be conveyed upwards, the defect that the crystal quality is affected and seed crystals are damaged and polluted due to the fact that the unstable atmosphere is formed in the early growth stage is overcome, and the separation plates block heat radiation of the raw material to the seed crystals, so that the sublimation of the surface of the seed crystal caused by no silicon carbide atmosphere supplement during impurity removal is avoided.

Description

technical field [0001] The invention relates to a silicon carbide crystal growth method and device, belonging to the technical field of silicon carbide crystal growth. Background technique [0002] Silicon carbide (SiC) crystals have excellent semiconductor physical properties such as high thermal conductivity, high breakdown voltage, extremely high carrier mobility, and high chemical stability. They can be made into high-frequency, High-power electronic devices and optoelectronic devices have great application value in the fields of national defense, high technology, industrial production, power supply, and power transformation, and are regarded as the third-generation wide-bandgap semiconductor materials with great development prospects. [0003] The growth process of silicon carbide crystals grown by PVT method is carried out in a closed graphite crucible. The silicon carbide powder (or silicon, carbon solid mixture) as the growth source is placed at the bottom of the cru...

AI Technical Summary

Problems solved by technology

Unstable atmosphere transmission will affect the nucleation of silicon carbide atmosphere on the seed crystal, which can easily induce defects such as polymorphism and dislocation, which will affect the quality of crystallization

At the same time, some impurities in the powder will be sublimated below the growth temperature of silicon carbide, and the transfer to the surface of the seed crystal will induce nucleation problems

The silicon carbide crystal growth methods and devices in the prior art cannot completely block the upward transportation of the silicon carbide atmosphere in the early stage of crystal growth, thereby affecting the nucleation of the silicon carbide atmosphere on the seed crystal, which easily induces defects such as polymorphism and dislocation, and affects the crystal. the quality of

Images