Abstract: 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.

Abstract: 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.

Abstract: A thin film of conductive high molecular compound is formed on a substrate such as Si followed by a heat treatment, and thereafter an electron beam exposure and subsequent development are made, to form pattern of the thin film of conductive high molecular compound; this method can eliminate forming of metal film to prevent the electron charge, can prevent charging of resist in electron-beam exposure or further prevent proximity effect when combined with deep ultraviolet light exposure.

Abstract: The invention relates to a developing solution of polydimethyl glutarimide containing acetone, ethyl alcohol, or propyl alcohol and, water, and alkali, and a pattern forming method using the same. According to the invention, a finer pattern than before may be formed by using PMGI resist film. At the same time, a liftoff process excellent in dimensional controllability and high in reliability than in the prior art will be realized. Besides, in the wet etching process of using the two-layer resist pattern of the invention as the mask on the GaAs substrate, since the adhesion of the lower layer resist to the substrate is superior, the recess width when etching the substrate can be stably controlled, so that a device of high performance may be obtained.