SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE

摘要

PURPOSE:To reduce leak current by making the concentration of impurities of source and drain areas of MISFET constituting memory cell to be different from that of source and drain areas of MISFET constituting peripheral circuit. CONSTITUTION:In a dynamic RAM, the concentration of impulities of a source area 8 and a drain area 9 of n-channel MISFET Q2 constituting memory cell is formed to be lower than that of a source area 6 and a drain area 7 of n- channel MISFET Q1 constituting peripheral circuit. Thus, the ion-implantation for forming the source area 8 and the drain area 9 of FETQ2 constituting the memory cell reduces crystal defect which occurs within a semiconductor substrate 1. It allows leak current of p-n junction between the areas 8 and 9 and the substrate 1 to be reduced for preventing the generation of refreshing failure.