| 摘要 |
PURPOSE:To operate a semiconductor integrated circuit at sufficiently low power voltage with a p-channel insulated gate type drain positive n-channel SIT gate commonly used as a load and a driver, respectively. CONSTITUTION:An n<+>-type layer 12 and an n<->-type layer 13 are formed on a p- type substrate 1, and p<+>-type layers 16, 17 and n<+>-type layers 14, 15 are formed at predetermined positions thereon. The p<+>-type layer 16 is the drain of the FET and the gate of the SIT. The n<+>-type layers 14, 12 are the source of the SIT and the buried drain thereof. A p<->-type layer 22 is now formed directly under the gate insulated film of the FET of the load, and the area density QSS of the positive charge at the insulating layer boundary is presented and there is relationship NA. d>=QSS where the NA represents the impurity density and d represents depth. When the NA.d is large, the current of the FET increased, and when the current of the FET is sufficiently increased, it becomes a depletion type. The density of the channel of the SIT and the size thereof are selected to be of type for normally opening. At this time the threshold voltage of the FET becomes not high but operates at lower voltage sufficiently. |
