Method of fabricating SiC semiconductor device

Abstract

In a method of fabricating a SiC semiconductor device, a surface of a SiC layer (5, 48, 102) is processed into a cleaned surface terminated at Si. An oxide film (7, 49, 105) is formed on the cleaned surface of the SiC layer. The SiC layer with the oxide film is subjected to thermal oxidation at a temperature in a range of 700° C. to 900° C. so that only terminal Si at the cleaned surface of the SiC layer is oxidated and an interface between the oxide film and the SiC layer becomes an SiO2 / SiC cleaned interface.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention generally relates to a method of fabricating a semiconductor device having basic portions made of silicon carbide (SiC). This invention specifically relates to a method of fabricating, for example, a SiC MOSFET.

[0003] 2. Description of the Related Art

[0004] There is a known semiconductor device including a SiC substrate or a 4H—SiC substrate. In the case where an oxide film (an SiO2 film) formed on a SiC substrate, especially a 4H—SiC substrate, is used as a gate oxide film, an interface level density is extremely high so that a channel mobility decreases. It is thought that the high interface level density is caused by impurity such as carbon which remains in an SiO2 / SiC interface between the gate oxide film and the SiC substrate. When the SiC substrate is thermally oxidated to form the gate oxide film, the oxidization causes carbon to remain in the SiO2 / SiC interface as impurity. On the other hand...

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