Patent ID: 7952128
Filing Date: 2011-05-31
Classification: H01L

Abstract:
1. A semiconductor device having a metal-oxide-semiconductor capacitor, the semiconductor device comprising: a silicon substrate of a first conductivity type; a lightly doped well region of a second conductivity type disposed by diffusing impurities into the silicon substrate; a charge accumulation region disposed in the lightly doped well region of the second conductivity type; a plurality of trenches disposed in the charge accumulation region; a heavily doped region of the second conductivity type disposed outside the charge accumulation region, and having a higher impurity concentration than an impurity concentration of the lightly doped well region of the second conductivity type; an oxide film disposed in the plurality of trenches disposed in the charge accumulation region, and on a surface of the silicon substrate of the first conductivity type; a polysilicon electrode disposed on the oxide film; and a substrate-side electrode disposed to make contact with the heavily doped region of the second conductivity type.