A silicon carbide epitaxial growth device

Abstract

The invention provides a device for epitaxial growth of silicon carbide. The cylindrical device is sequentially provided with a heating coil, a quartz wall, a graphite soft felt, a graphite support layer and a reaction cavity surrounded by the graphite support layer from outside to inside, wherein a gas inlet device and a gas outlet device are respectively arranged at two ends of the reaction cavity, a clad layer is plated on the inner wall of the graphite support layer, L-shaped gas supplementing tubes which are arranged side by side are parallel to the cylindrical device in axial direction, pass through the graphite soft felt and vertically pass through the graphite support layer, and clad layers are plated on the inner walls of the gas supplementing tubes. The gas provided by the gas supplementing tubes of the device compensates the lower part of the gas flow, so that the concentrations of the upper part and the lower part of the gas flow are generally the same, and the uniformity of the thickness of an epitaxial layer of silicon carbide is improved; gas phase nucleation in gas is inhibited, the growth rate is improved, and ultra thick silicon carbide epitaxial wafers with uniform height can be rapidly prepared. The device has a simple structure, is simple to manufacture and implement, has low manufacture cost, is easy to install and operate, and is applicable to industrial production; the epitaxial growth rate is high, and the quality of silicon carbide is good.

Description

technical field [0001] The invention relates to a crystal epitaxial layer growth device, in particular to a silicon carbide epitaxial growth device. Background technique [0002] Silicon carbide (SiC) is the third-generation semiconductor material developed after the first-generation semiconductor materials silicon, germanium and the second-band semiconductor materials gallium arsenide and indium phosphide. The wide bandgap of silicon carbide materials is silicon and arsenide 2 to 3 times that of gallium, so that semiconductor devices can work at a relatively high temperature (above 500 ° C) and have the ability to emit blue light; the high breakdown electric field is an order of magnitude higher than that of silicon and gallium arsenide, which determines the semiconductor device. Excellent high-voltage and high-power performance; high saturated electron drift velocity and low dielectric constant determine the high-frequency and high-speed operating performance of the device...

AI Technical Summary

Problems solved by technology

[0006] High-voltage silicon carbide power electronic devices require an epitaxial layer thickness of tens of microns to hundreds of microns, and a device with a general voltage of 10kV requires an epitaxial thickness of about 100um, while the current mature silicon carbide epitaxial growth rate is only about 5-7um / h , if a 100um thick silicon carbide epitaxial material is grown at such a growth rate, it will take 14-20 hours, which obviously greatly increases the manufacturing cost, and with the extension of the epitaxial growth cycle, more pollutants will be deposited on the reaction chamber wall , and then pollute the epitaxial wafer, so in order to grow high-quality, thick silicon carbide epitaxial wafers, the growth rate of epitaxy must be increased

[0007] The possible reason for the slow growth rate is that the decomposition rate of the reaction source gas is low and the easily formed silicon aggregates in the reaction gas. How to increase the growth rate is to improve the decomposition rate of the reaction source or suppress the generation of silicon aggregates. In the prior art , by introducing Cl compounds into the reaction gas flow, the etching effect of Cl elements is used to inhibit the formation of silicon aggregates, so as to increase the growth rate, but the introduction of Cl compounds requires additional gas pipelines and other equipment, and contains Cl The tail gas of the elements is extremely polluting to the environment

Images