Abstract: A semiconductor device includes a semiconductor part; first and second electrodes respectively on back and front surfaces of the semiconductor part; and a control electrode between the semiconductor part and the second electrode. The control electrode is provided inside a trench of the semiconductor part. The control electrode is electrically insulated from the semiconductor part by a first insulating film and electrically insulated from the second electrode by a second insulating film. The control electrode includes an insulator at a position apart from the first insulating film and the second insulating film. The semiconductor part includes a first layer of a first conductivity type provided between the first and second electrodes, the second layer of a second conductivity type provided between the first layer and the second electrode and the third layer of the first conductivity type selectively provided between the second layer and the second electrode.

Abstract: A method for manufacturing a semiconductor device of the present disclosure includes: ion-implanting impurities into a source-drain electrodes forming region where a source electrode and a drain electrode are to be formed on a nitride semiconductor layer formed on a substrate; forming a silicon nitride film on the surface of the nitride semiconductor layer by a plasma-enhanced chemical vapor deposition method, the silicon nitride film constituting a surface protecting sacrifice film and having a refractive index of 1.80 or more and less than 1.88 and a thickness of 100 nm or more and 500 nm or less; and heat-treating the nitride semiconductor layer on which the surface protecting sacrifice film is formed.

Abstract: Proposed is a method for the preparation of an aqueous slurry of calcium carbonate particles suitable as a base pigment in the preparation of a paper coating composition having excellent water retentivity and high solid concentration with good flowability, which contains precipitated and ground calcium carbonate particles in combination in a specified weight proportion and characterized by several parameters. The aqueous slurry is prepared in a process comprising the steps of: (a) subjecting an aqueous slurry or wet cake containing a specified amount of specific precipitated calcium carbonate particles to a primary dispersing treatment using a mixer to a specified extent; (b) admixing the aqueous slurry with a specified amount of specific ground calcium carbonate particles; (c) subjecting the aqueous slurry to a secondary dispersing treatment using a mixer to a specified extent; and (d) subjecting the aqueous slurry to a tertiary dispersing treatment using a sand grinder to a specified extent.