Patent ID: 7928515

Claim:
A semiconductor device comprising: a CMOS transistor having gate electrodes with different conducting types on a substrate; a trench capacitor type memory on a same substrate with the CMOS transistor; and a trench of the substrate for the trench capacitor including a dielectric film formed in the trench, a first poly silicon film formed inside of the trench, and a cell plate electrode located above the dielectric film; wherein the cell plate electrode includes the first poly silicon film formed on the dielectric film to not completely fill the trench, and a second poly silicon film formed on the first poly silicon film to completely fill the trench; wherein the second poly silicon film has a film thickness for forming the gate electrodes and the first poly silicon film; wherein an impurity concentration of the first poly silicon film in the trench of the cell plate electrode is higher than an impurity concentration of the second poly silicon film filled inside of trench of the cell plate electrode.