| 摘要 |
PROBLEM TO BE SOLVED: To enable increase of charge storage amount of a capacitance element, by forming an anti-oxidizing film on the surface of a lower part electrode, a dielectric film constituted of a high permitivity film on the surface of the anti-oxidiging film, and an upper electrode on the surface of the dielectric film. SOLUTION: A capacitance element C of a memory cell is formed on the surface of an interlayer insulating film 11, and constituted of STC structure wherein a lower electrode 15, a dielectric film 17 and an upper electrode 18 are laminated in order. In the capacitance element C, an anti-oxidzing film 16 constituted of a silicon nitride Si3 N4 film is formed between the lower electrode 15 and the dielectric film 17. Since composition balance of Si and N is stable in the silicon nitride, reaction between Si of the lower electrode 15 constituted of a silicon film 14 and O5 of the dielectric film 17 constituted of tantalum pentoxide Ta2 O5 film can be prevented. The upper electrode 18 of the capacitance element C is constituted of a tungsten film, and covered with an interlayer insulating film. |
