Abstract: A method for manufacturing a semiconductor device includes the steps of forming a P-type region on a surface of a semiconductor substrate, forming at least one Al electrode on the P-type region, forming an interlayer film in contact with the at least one Al electrode, the interlayer film being of a material which is less reactive with Si than is Al, and forming a semi-insulating film on the interlayer film, the semi-insulating film containing Si.

Abstract: A semiconductor substrate has a trench in a first main surface. An insulated gate field effect part includes a gate electrode formed in the first main surface. A potential fixing electrode fills the trench and has an expanding part expanding on the first main surface so that a width thereof is larger than the width of the trench. An emitter electrode is formed on the first main surface and insulated from the gate electrode electrically and connected to a whole upper surface of the expanding part of the potential fixing electrode. Thus, a semiconductor device capable of enhancing reliability in order to prevent an aluminum spike from generating and a manufacturing method thereof can be provided.

Abstract: The object of the invention is to improve a characteristic under a reverse bias. A P base layer (6) is provided as a plurality of band-shaped portions parallel with each other. A P+ base layer to be a downward protrusion having a high impurity concentration is not formed in a bottom portion of the P base layer (6). The P base layer (6) is formed more shallowly than an N layer (17), and furthermore, the band-shaped portions forming the P base layer (6) are coupled to each other at ends thereof. Moreover, an N source layer (5) is ladder-shaped and is connected to a source electrode (16) through only a crosspiece portion thereof.

Abstract: The object of the invention is to improve a characteristic under a reverse bias. A P base layer (6) is provided as a plurality of band-shaped portions parallel with each other. A P+ base layer to be a downward protrusion having a high impurity concentration is not formed in a bottom portion of the P base layer (6). The P base layer (6) is formed more shallowly than an N layer (17), and furthermore, the band-shaped portions forming the P base layer (6) are coupled to each other at ends thereof. Moreover, an N source layer (5) is ladder-shaped and is connected to a source electrode (16) through only a crosspiece portion thereof.