| 摘要 |
<p>PURPOSE:To enable execution of stable writing, erasure and reading, to increase component density and to facilitate manufacture by laminating a thin film transistor for selection on a thin film transistor for a memory and by enlarging the film thickness of an upper gate insulation film. CONSTITUTION:A thin film transistor TrT10 for a memory and a thin film TrT20 for selection are constructed in lamination, while an upper gate insulation film 16 is constructed of a lower layer film 16a and an upper layer film 16b and made thick on the part of a semiconductor layer 14 corresponding to a memory area. Accordingly, insulative separation can be attained without fail between the region of the TrT20 in the layer 14 and a lower gate electrode G10 of the TrT10 and between the TrT10 and an upper gate electrode G20, respectively. According to this constitution, a malfunction due to the effect of a gate voltage is prevented and the TrT10 and the TrT20 are made to operate normally, so that stable writing, erasure and reading can be executed. Besides, component density is increased by lessening the element area of the memory, and the memory can be manufactured by a reduced number of processes.</p> |
