| 摘要 |
PURPOSE:To equalize the characteristics of a RAM having high capacitance by forming a charge storage region and an electrode for capacitance through a self alignment system. CONSTITUTION:A field oxide film 2 and a gate oxide film 3 are formed onto a p type Si substrate 1. n<+> Poly Si 7 is stacked through a CVD method, and coated with SiO2 14. A negative type resist mask 15 is executed and B ions are implanted and a p<+> shielding region 5 is shaped, and As ions are inplanted and the n<+> storage region 6 is formed. When the SiO2 14 is etched in the HF of five Torr at the normal temperature, only the SiO2 under the mask 15 is removed selectively through etching. The mask 15 is removed, the n<+> poly Si 7 is patterned while using the SiO2 14 as a mask, the mask 14 is taken off, and the RAM type one transistor-one capacitance memory having double electrode structure by the Poly Si is completed through a conventional method. According to this constitution, the characteristics slightly vary because positional displacement is not generated between the charge storage region and the capacitance electrode. |
