| 摘要 |
PURPOSE:To inhibit a crystal defect and the spread of trench width by burying capacitor electrodes into all trenches through insulating films while the insulating films are thinned in sections except the bottom sides of the trenches and thickened in trenches except capacitor forming regions and the bottoms of the trenches. CONSTITUTION:In a semiconductor storage device in which a memory cell is constituted of a MOS transistor and a MOS capacitor and capacitors are shaped to one parts of trenches 13 for element isolation formed to the surface of a semiconductor substrate 11, capacitor electrodes 16 are buried into all trenches 13 through insulating films 14, 15 shaped onto the wall surfaces of the trenches 13. The insulating films 14, 15 are thinned in sections except the bottom sides of the trenches 13 in capacitor forming regions, and thickened in the trenches except the capacitor forming regions and the bottom sides of the trenches in the capacitor forming regions. Consequently, the difference of thermal expansion coefficients of substrate silicon and a buried material in the tranch can be reduced. Accordingly, the generation of a crystal defect in the silicon substrate is inhibited while leakage between cells and the generation of a parasitic transistor can be suppressed. |
