Silicon carbide device epitaxial structure and preparation method thereof

Abstract

An epitaxial structure of a silicon carbide device and a preparation method thereof relate to the technical field of semiconductor devices. The method includes: 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 injecting N through the first window type ions to form an N-type ion implantation region in the silicon carbide epitaxial layer; a continuous second barrier layer is grown on the first barrier layer and in the first window, and the second barrier layer encloses the first window to form a second window ; Etch the second barrier layer to expose the N-type ion implantation region at the second window, and retain the second barrier layer at the sidewall of the first window to form a sidewall structure; In the N-type ion implantation region by ion implantation A P-type ion implantation region is formed, and the implantation depth of the P-type ion implantation region in the silicon carbide epitaxial layer is greater than the implantation depth of the N-type ion implantation region in the silicon carbide epitaxial layer.

Description

technical field [0001] The invention relates to the technical field of semiconductor devices, in particular, to an epitaxial structure of a silicon carbide device and a preparation method thereof. Background technique [0002] Silicon carbide (SiC) material, as one of the representatives of the third-generation wide-bandgap semiconductor materials, has the characteristics of large band gap, high critical breakdown electric field, high thermal conductivity and high electron saturation drift speed, making it suitable for high-power, High temperature and high frequency power electronics have broad application prospects. [0003] In the traditional SiC diode fabrication 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 depletion regio...

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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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