SiC semiconductor element and manufacturing method thereof

摘要

Provided are a technology that simply forms a particular crystal surface such as a {03-38} surface having high carrier mobility in trench sidewalls and a SiC semiconductor element where most of the trench sidewalls appropriate for a channel member are formed from {03-38} surfaces. A trench structure formed in a (0001) surface or an off-oriented surface of a (0001) surface with an offset angle 8° or lower of SiC is provided. The channel member is in the trench structure. At least 90% of the area of the channel member is a {03-38} surface or a surface that a {03-38} surface offset by an angle from −8° to 8° in the <1-100> direction. Specifically, the trench sidewalls are finished to {03-38} surfaces by applying a thermal etching to a trench with (0001) surfaces of SiC. Thermal etching is conducted in a chlorine atmosphere above 800° C. with nitrogen gas as the carrier.

主权项

1. An SiC semiconductor device, wherein
trench sidewalls are formed from a basal plane of SiC having a crystal structure of any of a hexagonal crystal, a cubical crystal, and a rhombohedral crystal or formed from an off plane having an off angle of 8 degrees or less with respect to the basal plane, 50% or more of the area of the trench sidewall is a plane tilted at 54 to 55 degrees from the basal plane, and surfaces of the trench sidewalls are used as channel portions.