METHOD FOR PRODUCING A SUBSTRATE, SUBSTRATE, METAL OXIDE SEMICONDUCTOR FIELD EFFECT TRANSISTOR WITH A SUBSTRATE, AND MICROELECTROMECHANICAL SYSTEM WITH A SUBSTRATE

摘要

The invention relates to structured substrates for a metal oxide semiconductor field effect transistor or a microelectromechanical system comprising a silicon carbide layer (10) for example, on which a masking layer (60') that is structured using a direct lithographically structured photoresist is applied such that at least one region of the substrate is exposed in a method for producing a trench. The exposed region has a width which constitutes the minimum width that can be provided in the used photoresist using direct lithography. The method is characterized by the following steps: (a) applying a part (65') of a second masking layer on walls of the structured first masking layer, said walls adjoining the exposed region, in order to reduce the width of the exposed region, and (b) dry etching using the structured first masking layer (60') and the part (65') of the second masking layer. In this manner, a trench with a reduced width can be easily and inexpensively produced with a direct lithographically structured photoresist.