| 摘要 |
PURPOSE:To provide a DRAM manufacturing method by which a DRAM having substrate electrode type excavated-trench capacitors and minimizing memory cells can be manufactured through simple processes. CONSTITUTION:In this method for manufacturing a DRAM constituted by arranging memory cells each of which is constituted of one MOS transistor and one capacitor on an Si substrate 1, gate electrodes 13 are formed on part of the substrate 1 and trenches 8 after excavating the trenches 8 into memory cell areas of the substrate 1 and embedding storage electrodes 10 in the trenches 8 with capacitor insulating films 9 in between, and then, the upper surfaces of the electrodes 10 are covered with insulating films 11. Then an insulating film 17 is formed on the substrate 1 and contact holes are opened through the bit-line contacting sections and storage electrode connecting sections by using the gate electrodes 13 as a mask and the contact holes are filled up with conductive layers 181 or 182. Thereafter, the source diffusion layers 151 of MOS transistors are connected to the electrodes 10 and, at the same time, the drain diffusion layers 152 of the MOS transistors are connected to a bit line 21. |
