SILICON CARBIDE SEMICONDUCTOR DEVICE AND SILICON CARBIDE SEMICONDUCTOR DEVICE MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a silicon carbide semiconductor device and a silicon carbide semiconductor device manufacturing method, which can improve capacitance-voltage characteristics of an insulation film and achieve high initial characteristics and high reliability.SOLUTION: The silicon carbide semiconductor device manufacturing method comprises: first, selectively forming an element isolation insulation film 2 on a surface of an n-type SiC substrate 1; subsequently conducting thermal oxidation on the surface of the n-type Si substrate 1 in a halogen atom-containing or halogen compound-containing dry oxygen gas atmosphere thereby to form a thermally oxidized film 3 which functions as a gate insulation film thereby to remove carbon atoms near a boundary surface between the n-type SiC substrate 1 and the thermally oxidized film 3; subsequently conducting a heat treatment for densifying the thermally oxidized film 3 in an Ar gas atmosphere thereby to recover insulation characteristics of the thermally oxidized film 3; and subsequently depositing a polycrystalline silicon film 4 which functions as a gate electrode on the surface side of the n-type SiC substrate 1 so as to cover the thermally oxidized film 3 thereby to form a MOS capacitor composed of the N-type SiC substrate 1, the thermally oxidized film 3 and the polycrystalline silicon film 4.