Abstract: A semiconductor device includes a substrate, a semiconductor layer, an element region, and fin transistors. The substrate includes a principal surface. The semiconductor layer is formed as a surface layer or on the principal surface of the substrate, the surface layer being the principal surface of the substrate. The semiconductor layer has a crystal structure in which an angle between two of crystal orientations with equivalent relationships on a crystal plane having a correspondence with the principal surface of the substrate is 60 degrees or 120 degrees. The element region includes unit element regions formed on the principal surface of the substrate. The fin transistors are formed in the semiconductor layer, in the respective unit element regions. The fin transistors radially extend from a center toward an outer periphery of the element region. Adjacent two of the fin transistors have a spacing with a 60° angle or a 120° angle.

Abstract: A polyurethane varnish is used to impregnate an electrical coil and cure it. The impregnation and curing treatment method comprises a preliminary heating step in which an article having a coil is heated to a preliminary heating temperature at which the viscosity of the polyurethane varnish decreases and is above the drying temperature, a varnish application step in which the polyurethane varnish is continuously applied to the coil while rotating the heated article at a constant speed, and a high-temperature rotary drying step in which the polyurethane varnish is dried while heating said polyurethane varnish at a drying temperature which is higher than the varnish temperature during the varnish application step.