| 摘要 |
PURPOSE:To form a transfer transistor having high storage capacity and high reliability by strengthening breakdown strength and flatness of a gate electrode, a bit line and a storage electrode. CONSTITUTION:An Si substrate 11 is selectively locally oxidized to form a field oxide film 12, and N<+> type impurity diffused layers 13, 14 are formed by thermal ion diffusing as the source, drain of a transfer transistor T1. A storage electrode 22a formed on a polysilicon film containing impurity ions of a desired thickness is heat treated thereby to form a dielectric film 23. SiO2 films 15a, 16, 19a, 20 or Si3N4 film 20 are formed as thick insulating films on the sidewalls of gate electrodes WL3, WL4 and a bit line BL1. Thus, even if the electrode 22a is stereoscopically laminated as a result of miniaturization, the breakdown strength and flatness of the electrodes WL3, WL4 and the line BL1 can be strengthened. |
