| 摘要 |
PURPOSE: To perform integration into a small area by forming a current- detecting type cell structure using three elements in a solid structure. CONSTITUTION: A cell structure is in BiCMOS form, consisting of an n-channel MOSFET 17 and an n-channel JFET 18 and a PNP bipolar transistor 19. The n-channel MOSFET 17 functions as a MOS capacitor that is constituted of polysilicon gate oxide and a P region, while it is kept constantly turned off. The n-channel JFET 18 reads information stored in the capacitor of the MOSFET 17. The PNP bipolar transistor 19 is used to write data into a cell and selectively charges or discharges the MOS capacitor. In the case of a reading-mode operation, the bipolar transistor 19 is cut off. Since the cell is a current-detection system, it can be reduced to a substantially small area, thus increasing the reading and writing speeds. |
