SEMICONDUCTOR MEMORY DEVICE

摘要

PURPOSE:To increase integration degree, by providing a similarly conductive semiconductor layer on the main surface of a semiconductor substrate, and installing a memory capacitor thereupon and a transfer transistor on its side. CONSTITUTION:A P type Si-substrate 11 is separated at an SiO2 layer 12. A P layer 13 is accumulated on its main surface selectively. A bit line of N<+> diffusion layer 14 is made on its main surface. A memory capacitor is constituted by covering with an SiO2 film 15 and piling up a poly Si layer 17 on the P layer 13. A field effect transfer transistor is constituted as a channel of the layer 13 side 18. This constitution arranges the transfer transistor vertically. The area occupancy is reduced and the integration degree is increased.