| 摘要 |
PURPOSE:To provide a power supply wiring having a greater removal effect of power supply noise by forming a large capacity bypass capacitor between the power supply and the earth so as to reduce parasitic resistance. CONSTITUTION:A ground wiring 2 is laid holding a power supply wiring 1 from opposite ends of the ground wiring 2. A gate oxide film 3 and a gate 4 are formed below the power supply wiring 1. An n region 8 is formed at the end of the gate oxide film as ground potential. A p region 9 is formed over a remaining almost all portions below the ground wiring for substrate contact. Since the potential of the gate is equal to a power supply, an inversion layer is formed below the oxide film, which forms the ground potential through the n region. A capacitor is formed by holding the gate oxide film between the gate and the inverted layer. Since the size of the capacitor is about half the half of the power supply wiring in its length and is substantially equal to the length of the power supply, parasitic resistance produced on the gate and the inversion layer is suppressed to be lower and gate capacitance corresponding to the area of the main power supply wiring are connected between the power supply and the earth. |
