| 摘要 |
PURPOSE:To make the fluctuation in supplied power source voltage due to transit current small and to stabilize the voltage, by simultaneously forming a large capacitor in a semiconductor substrate directly beneath a metallic power source wiring layer and a grounding wiring layer, and connecting the capacitor to a power supply metal wiring. CONSTITUTION:A grounding potential is imparted to a P-type well 102 from grounding potentials 303' and 302' through a P-type semiconductor layer 103. A power source voltage is imparted to a first metal layer 301 from a third metal layer 303 and a second metal layer 302. A capacitor can be formed with a first metal layer 301, an oxide film 201' and the P-type well 102. Since an oxide film 201 is a thin oxide film, the large capacitor can be connected to a power supply metal wiring, which is constituted by the second metal layer and the third metal layers 302 and 303. The fluctuation in potential due to transient current flowing in a power source wiring can be suppressed by the large capacitor. Since the capacitor is formed directly beneath the power source wiring, the expansion of the occupying area of the power source wiring region can be suppressed.
|
