| 摘要 |
PURPOSE:To stabilize a channel forming region thereby to be able to laminate regions in a thin film semiconductor device by elevationally interposing the channel forming region of a thin film semiconductor region between gate electrodes. CONSTITUTION:A second gate electrode 22 which becomes a lower gate electrode of a first thin film semiconductor region 25 is selectively formed on a semiconductor substrate 21, and a third gate insulating film 24 is formed on the surface. A first thin film semiconductor region 25, a first gate insulating film 26, a first gate electrode 27, a second gate insulating film 28, a second thin film semiconductor layer 29, a fourth gate insulating film 30, and a third gate electrode 31 are sequentially formed thereon. The channel forming regions 34 and 37 of first and second MOS transistors 43 and 44 are elevationally interposed between upper and lower gate electrodes 27 and 22, 31 and 27, respectively. Thus, with one gate electrode as a stationary electrode the potential of the channel forming region is stabilized, and the other gate electrode can be used as a signal input electrode. |
