Manufacturing method of gate oxide layer of SiC MOSFET device

Abstract

The invention provides a manufacturing method of a gate oxide layer of a SiC MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) device. The manufacturing method comprises the steps of providing a SiC substrate and a first oxide layer, wherein the first oxide layer is located on the surface of the SiC substrate; forming a second oxide layer on the surface, far away from the SiC substrate, of the first oxide layer by adopting a high-temperature low-pressure chemical vapor deposition method; and annealing the first oxide layer and the second oxide layer, wherein the first oxide layer and the second oxide layer after annealing form a gate oxide layer. In the method, due to the existence of the first oxide layer, when the second oxide layer is generated, the second oxide layer does not react with the silicon carbide epitaxial wafer, and no redundant by-product is generated, so that the SiC / SiO2 interface quality of the gate oxide layer is relatively good, and the problem of relatively low channel mobility of a SiC MOSFET in the prior art is solved.

Description

technical field [0001] The present application relates to the field of semiconductors, in particular, to a method for fabricating a gate oxide layer of a SiC MOSFET device and the SiC MOSFET device. Background technique [0002] SiC is an important wide-bandgap semiconductor material and has important applications in power semiconductor devices. However, due to the large number of interface states near the conduction band edge, its device field-effect mobility is only 20–50 cm2 / Vs, about 1.5 orders of magnitude lower than its bulk material mobility, which greatly limits the performance of SiC devices. SiC / SiO 2 Interface state density ratio of classical Si / SiO 2 The interface state density is more than 2 orders of magnitude higher. The chemical characteristics of these defects have not yet fully reached a consensus, but a large number of interface state defects become traps that hinder the speed of electron movement, which is one of the reasons for low electron mobility a...

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Problems solved by technology

[0005] The main purpose of this application is to provide a method for fabricating a gate oxide layer of a SiC MOSFET device and a SiC MOSFET device, so as to solve the problem of low channel mobility of SiC MOSFETs in the prior art

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