Abstract: To provide a semiconductor substrate and a light-valve semiconductor substrate capable of preventing the threshold value of a MOS transistor on a single-crystal silicon device forming layer from increasing and forming a MOS integrated circuit with a high reliability even for a long-time operation. A semiconductor substrate and a light-valve semiconductor substrate comprising a single-crystal silicon thin-film device forming layer 5001 formed above an insulating substrate 5004 through an adhesive layer 5003 and an insulating layer 5002 formed on the single-crystal silicon thin-film device forming layer, wherein a heat conductive layers 5201 and 5202 made of a material with a high heat conductivity are arranged between the single-crystal silicon thin-film device forming layer and the adhesive layer and on the insulating layer.

Abstract: An apparatus for forming a thin film irradiates an electron beam on a vaporizable substance held in a crucible. A pair of electromagnets are disposed in coplanar relation and at right angles to each other to generate a magnetic field which deflects the electron beam. An alternating current is applied to the electromagnets to generate the magnetic field, and the magnitude and frequency of the current are controlled so as to scan the electron beam in a circular pattern on the vaporizable substance.