Silicon-carbide power device of heterojunction terminal and preparation method of silicon-carbide power device

Abstract

The invention discloses a silicon-carbide power device of a heterojunction terminal. The silicon-carbide power device comprises a cathode electrode, a substrate layer, an N-type SiC epitaxial layer and an anode electrode, and further comprises a plurality of separate and independent P-type structures, wherein the P-type structures are formed by P-type semiconductor materials, the growth temperature of which is lower than that of the SiC, formed on the N-type SiC epitaxial layer through heteroepitaxial growth, and the P-type structures are at least distributed on the periphery of the anode electrode so as to form the heterojunction terminal. Therefore, influence to doping characteristics of the N-type SiC epitaxial layer is effectively avoided, and a silicon-carbide device with high breakdown voltage and low device threshold voltage can be obtained. The invention further discloses a manufacturing method of the silicon-carbide power device of the heterojunction terminal, requirements of the high temperature complex technique are largely reduced, the manufacturing procedure is simple, and the manufacturing costs are reduced.

Description

technical field [0001] The invention relates to a semiconductor device, in particular to a heterojunction-terminated silicon carbide power device and a preparation method thereof. Background technique [0002] Power devices based on wide-bandgap semiconductor materials (such as silicon carbide (SiC), gallium nitride (GaN)) can provide greater breakdown voltage and power density, and are expected to be widely used in next-generation power conversion. In SiC power devices, due to the discontinuity of the junction, the electric force lines tend to concentrate at the edge of the junction, resulting in the existence of a high electric field at the junction edge. The presence of a high field will lead to premature breakdown at the junction edge, which greatly limits the reverse breakdown voltage of the device. Therefore, in the design and manufacture of SiC power devices, various junction termination technologies are often used to alleviate the edge electric field concentration e...

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Problems solved by technology

Among them, epitaxial growth is to directly grow P-type SiC on the entire surface of N-type SiC layer. Since the growth temperature of P-type SiC is often high (>1500°C), some P-type impurities (such as Al) will inevitably diffuse during the growth process. In weak N-type SiC, self-doping is formed on the surface of N-type SiC, and even the area is converted into P-type, which leads to changes in the doping characteristics of the N-type SiC surface, which in turn affects the acquisition of low device turn-on voltage; P for SiC Type ion implantation often requires advanced equipment such as high-temperature ion implanters and ultra-high temperature annealing furnaces to complete, and has complex manufacturing processes and high costs, which restricts its industrial development

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