Abstract: A semiconductor apparatus having a region for isolation between devices comprises a semiconductor substrate, a polycrystalline silicon layer portions selectively formed to be spaced apart from each other on the semiconductor substrate, an impurity diffused region formed under the polycrystalline silicon layer, and a silicon oxide film for filling in a space between the respective adjacent portions of the polycrystalline silicon layer. The impurity diffused region constitutes a source or drain region of a field effect device such as a MOS transistor isolated by the silicon oxide film.

Abstract: A semiconductor memory device comprises a semiconductor substrate having a trench, first polysilicon serving as a charge storage region formed through an insulating film in an inner portion of the trench, and second polysilicon serving as a capacitor electrode formed through an insulating film inside of the first polysilicon, the charge storage regions being connected to a transfer gate in the upper end of the concave portion so that information charges are transferred.

Abstract: A method of manufacturing a semiconductor device comprises the steps of forming memory cell portions (2, 4, 6, 11) on a p.sup.- -type semiconductor substrate (1), forming a gate insulator film (5) and a gate electrode (3) each having a larger width, by approximately 1 .mu.m, than the original width, ion-implanting p-type impurities utilizing the gate insulator film (5) and the gate electrode (3) as masks, to form p.sup.+ -type regions (120, 121), etching the side walls of the gate insulator film (5) and the gate electrode (3) to the original width and then, ion-implanting n-type impurities utilizing these regions as a mask, to form n.sup.+ -type regions (80, 81), and heat-treating these regions (80, 81, 120, 121), to form regions (80a, 81a, 120a, 121a). The p.sup.+ -type regions (120a, 121a) prevent passage of electrons out of electron-hole pairs induced by alpha rays, to prevent occurrence of soft errors. The p.sup.+ -type regions (120a, 121a) are located inside the n.sup.