| 摘要 |
PURPOSE:To form the MOS dynamic memory, the quantity of charges stored therein is large, the holding time of charges stored therein is long and in which there occurs hardly a soft error, by forming an insulating film for obstructing junction leakage currents in the MOS dynamic memory of one transistor one capacitor. CONSTITUTION:The insulating film 13 for obstructing junction leakage currents is formed between an n<+> type impurity region 4 formed in a p type silicon base body 1 and a p<+> type impurity region 12 for being changed into high capacitance formed in the base body 1 under the n<+> type impurity region 4. When the impurity concentration of the p<+> type impurity region 12 is N, the quantity of charges stored QS can be augmented with the increase of N and the holding time QS/dQS/dt of charges stored can also be lengthened because QS/dQS/dt augments with the increase of N when x is 10<-6>cm in the thickness x of the insulating film 12. When x is made smaller than 10<-6>cm, there is a tendency of which QS/dQS/dt decreases suddenly by the increase of leakage currents, but the holding time of charges stored is improved considerably because leakage currents are of an extremely small value. |
