A sic Schottky diode and method of making the same

Abstract

The invention discloses a SiC Schottky diode and a manufacturing method of the SiC Schottky diode. The SiC Schottky diode comprises an N++-SiC substrate and an N--SiC epitaxial layer, wherein the N--SiC epitaxial layer is formed on the N++-SiC substrate, an N-type ohmic contact electrode is arranged on the reverse side of the N++-SiC substrate, a Schottky contact electrode is arranged on the surface of the N--SiC epitaxial layer, a selective P+-SiC area ring is arranged at the bottom of the Schottky contact electrode, an N+-SiC area ring which corresponds to the P+-SiC area ring is arranged at the bottom of the P+-SiC area ring, and serves as a protective ring when avalanche breakdown is carried out, a plurality of P+-SiC protective rings are arranged at the periphery of the Schottky contact electrode, and serve as a terminal protective structure of a diode device, a SiO2 passivation layer is arranged on the edge of the Schottky contact electrode, and a field plate is arranged on the top of the SiO2 passivation layer. According to the SiC Schottky diode and the manufacturing method of the SiC Schottky diode, the break-over voltage of the SiC Schottky diode can be close to the break-over voltage of a Si Schottky diode, and the SiC Schottky diode is in good cooperation with an existing system with a Si device, and can be applied to a switching power source with the high voltage ranging from 600V to 1200V and a power factor correction circuit, wherein the high voltage cannot be achieved when the Si Schottky device is used.

Description

Technical field

[0001] The invention relates to the technical field of semiconductor devices, in particular to a SiC Schottky diode with low on-voltage and a manufacturing method thereof. Background technique

[0002] Wide-bandgap semiconductors generally refer to silicon carbide (SiC), gallium nitride (GaN) and other such as those with a forbidden band width of about 3.0 eV or more. Compared with Si materials, these materials have the advantages of wider band gap, high breakdown electric field, high thermal conductivity, high electron saturation rate, etc., and are preferred materials for the preparation of power electronic devices. Among them, Schottky diodes made of SiC materials are majority carrier devices. The structure is characterized by no additional carrier injection and storage, fast switching speed, and low switching loss. It can be widely used in electric vehicles / hybrid power Vehicles and other inverters, converters, PFC circuits that require power conversion, as w...

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