JPS6457642A - Semiconductor device - Google Patents

Abstract

PURPOSE:To reduce the leak current between elements, and improve the radiation resistance, by forming a polysilicon film, via a silicon thermal oxide film, on the side surface of a groove to isolate a plurality of element forming regions, and forming a multilayers of a plurality insulative material so as to fill the groove. CONSTITUTION:The title device is provided with the following; a groove selectively formed on a main surface of a silicon semiconductor substrate 101, a plurality of element forming regions isolated by said groove, a silicon thermal oxide film 106 formed on the side surface of said groove, a polysilicon film 107 formed on the side surface of the groove inside the polysilicon thermal oxide film 106 so as to be in contact with the silicon thermal oxide film 106, and multilayers 108, 109 of a plurality of insulative materials formed in the multiplexing manner in the groove so as to fill the groove where said polysilicon film 107 is formed. A plurality of insulative materials mentioned above are one of, e.g., silicon nitride, phosphate glass, boron phosphate glass, and silicon oxide. For example, a channel stopper region 105 is previously formed at the part being in contact with the groove of the substrate 101, and a MOS transistor is formed in the element forming region.