| 摘要 |
PROBLEM TO BE SOLVED: To prevent the mutual diffusion of impurities in a gate electrode by forming a gate electrode in the logic region of a substrate of material, which does not include impurities and by forming a contact portion to be a memory node contact portion and then by removing the gate electrode of the logic region, such that the lower layer side thereof is left and then by forming the removed portion again. SOLUTION: A gate insulating film and a gate electrode 11 are formed on a semiconductor substrate in the cell region of a DRAM cell portion. A gate insulating film and a gate electrode 11 made of material which does not include impurities are formed on a semiconductor substrate 1 in the logic region of a logic portion. A substrate 17 having a diffusion layer 15 and a silicon oxide film 16 is prepared. A plug 23 for connecting the diffusion layer 15 to the silicon oxide film 16 of the cell region is formed of silicon material, including impurities and then the silicon oxide film 16, is removed until the gate electrode 11 is exposed. The gate electrode of a part of the logic region is removed so that a lower layer side thereof is left, and then impurities are re-introduced into the remaining portion of the gate electrode to form the removed portion of the gate electrode 11. |
