Chemical vapor deposition equipment used for producing silicon carbide epitaxial wafer

Abstract

The invention provides a method for improving the uniformity of silicon carbide epitaxial wafer, and the method can be used to produce silicon carbide epitaxial wafers with an even thickness. The method comprises the following steps: installing an air flow blocking ring under the air flow of a reaction cavity, then placing a silicon carbide substrate on a supporting platform, heating the reaction cavity to a temperature required by the epitaxy, and introducing reaction gas and carrier gas so as to finally form a silicon carbide epitaxial layer on the silicon carbide substrate. The silicon carbide epitaxial wafer obtained by the method has a more even thickness, besides the equipment is simple, so the method is a most practicable and cheapest method for improving conventional equipment, does not need much investment, and is benefit for the industrial production.

Description

【Technical Field】 [0001] The invention belongs to the field of chemical vapor deposition, and specifically relates to a chemical vapor deposition equipment for producing silicon carbide epitaxial wafers. 【Background technique】 [0002] Silicon carbide (SiC) is the third-generation wide-bandgap semiconductor material. It has the characteristics of wide band gap, high critical breakdown electric field, high thermal conductivity, and high carrier saturation drift speed. It is especially suitable for the production of high-temperature, high-voltage, high-power power electronics Such semiconductor devices are of great significance to the development of industries such as hybrid electric vehicles, electric vehicles, solar inverters, and smart grids. [0003] The production of silicon carbide materials is not easy, whether it is crystal growth or epitaxial growth. Growing high-quality epitaxial wafers is a challenge to the process. The traditional chemical vapor deposition method to grow...

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Problems solved by technology

[0004] The patent number is ZL98812328.2, and the patent titled "Growing very uniform silicon carbide epitaxial layer" discloses an improved chemical vapor deposition method. The reactor is heated until the silicon carbide raw material gas forms an epitaxial layer on the substrate in the reactor. The temperature of the raw material gas and the carrier gas flow through the heated reactor to form a silicon carbide epitaxial layer on the substrate. At the same time, the carrier gas includes a mixture of hydrogen and a second gas, wherein the thermal conductivity of the second gas is lower than that of hydrogen. lead, so that the consumption of the raw material gas when passing through the reactor is lower than that of using a single hydrogen as the carrier gas, but the operation process is complicated, and an additional gas source is added, which increases the manufacturing cost

In recent years, silicon carbide epitaxy technology has been very mature in low-voltage devices, but there are still many shortcomings in silicon carbide thick epitaxy technology in high-voltage devices, such as the difficulty of achieving thicker silicon carbide epitaxial layers due to uniformity and surface defects; The growth rate is too low, making the thick SiC epiwafers required to grow high-voltage devices prohibitively expensive

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