Patent ID: 10242876

Abstract:
Provided is a method including the following steps: forming an insulating film having a thickness of 0.5 μm or greater on an epitaxial layer provided with a well region, a source region, and a contact region, each being an impurity diffusion region; forming, in the insulating film, an opening that has a dimension of 2 mm×2 mm or greater in a plan view to expose at least part of the impurity diffusion region from the insulating film. The step of forming the opening in the insulating film is performed by the following separate steps: removing the insulating film so as to leave one-half or less of the thickness of the insulating film unremoved, through dry etching by the use of a photoresist; and removing the insulating film until the opening reaches the upper surface of the epitaxial layer, through wet etching by the use of the same photoresist.