Abstract: In a semiconductor device of the type in which a bipolar element and MOS field-effect transistors are formed on one surface of a semiconductor substrate, this invention discloses a semiconductor device characterized in that first buried layers of a first conductivity type are formed within regions of the semiconductor substrate in which the bipolar element are formed, a second buried layer of the first conductivity and at least one MOS field-effect transistor type is formed within the semiconductor substrate facing at least the emitter of the bipolar element, and the depth from one surface of the semiconductor substrate to the second buried layer of the first conductivity type is less than the depth from that surface to the first buried layer of the first conductivity type.This invention can prevent any increase in the capacity of the MOS field-effect transistor, and can also improve the operating speed of the bipolar element.

Abstract: In a semiconductive photodetector device having a semiconductor substrate and a plurality of photodiodes juxtaposed in one major surface of the semiconductor substrate, exposed edges of adjacent pn junctions of adjacent photodiodes are covered with a polysilicon film.

Abstract: An insulating film is formed on a semiconductor substrate, and the insulating film on that part of the semiconductor substrate where an emitter is to be formed, is removed to expose the surface of the above part. A polycrystalline or amorphous silicon film is deposited on the entire surface, and then irradiated with a laser beam to convert that portion of the polycrystalline or amorphous silicon film which is deposited on the surface of the semiconductor substrate without interposing the insulating film therebetween, into a single crystal of silicon, thereby forming a stacked emitter.

Abstract: A semiconductor diode consists of a low resistivity n conductivity type semiconductor substrate, a high resistivity n conductivity type semiconductor layer, formed on the surface of the substrate, a high resistivity p conductivity type semiconductor layer, whose thickness is smaller than the diffusion length of electrons, formed on the n conductivity type layer, a metal electrode forming a Schottky barrier contact with the p conductivity type layer, and an electrode forming an ohmic contact with the substrate.

Abstract: An insulated gate field effect transistor formed on one main surface of a semiconductor substrate comprises a drain region the impurity concentration of which is lower than twice that of the semiconductor substrate and the conductivity type is reverse to that of the substrate and a region of a high impurity concentration, formed in the low impurity concentration region, the conductivity type of which is the same as that of the low impurity concentration region.