Epitaxial structure of silicon carbide device and preparation method thereof

Abstract

A silicon carbide device epitaxial structure and a preparation method thereof relate to the technical field of semiconductor devices. The method comprises the following steps: growing a silicon carbide epitaxial layer on a substrate; depositing a first barrier layer on the silicon carbide epitaxial layer; etching the first barrier layer to form a first window exposing the silicon carbide epitaxial layer, and implanting N-type ions through the first window to form an N-type ion implantated region in the silicon carbide epitaxial layer; growing a continuous second barrier layer on the first barrier layer and in the first window, wherein the second barrier layer is enclosed in the first window to form a second window; etching the second barrier layer to expose the N-type ion implanted region at the second window, and reserving the second barrier layer on the side wall of the first window to form a side wall structure; and forming a P-type ion implanted region in the N-type ion implanted region through ion implantation, wherein the implantation depth of the P-type ion implanted region in the silicon carbide epitaxial layer is greater than that of the N-type ion implanted region in the silicon carbide epitaxial layer.

Description

technical field [0001] The invention relates to the technical field of semiconductor devices, in particular to a silicon carbide device epitaxial structure and a preparation method thereof. Background technique [0002] As one of the representatives of the third-generation wide bandgap semiconductor materials, silicon carbide (SiC) material has the characteristics of large bandgap width, high critical breakdown electric field, high thermal conductivity and high electron saturation drift velocity, making it suitable for high-power, The field of high temperature and high frequency power electronics has broad application prospects. [0003] In the traditional SiC diode manufacturing process, an N-type region is formed by epitaxial growth, and a P-type region is formed by ion implantation. However, in the prior art, a wide depletion region will be formed between the P-type region formed by ion implantation and the N-type region formed by epitaxial growth, and this part of the d...

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Problems solved by technology

However, in the prior art, a wide depletion region will be formed between the P-type region formed by ion implantation and the N-type region formed by epitaxial growth, and this part of the depletion region will block the current diffusion during forward conduction. , increasing the resistance during forward conduction

At the same time, due to the high-temperature activation process after silicon carbide ion implantation, the P-type region will expand outward, which will further increase the on-resistance

Under the same chip area, the greater the forward conduction resistance, the lower the current density of the device and the lower the energy efficiency

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