Patent ID: 7383528

Claim:
A method for checking an IC layout, the IC layout comprising a first and a third power supply layers for transmitting power and a second metal layer disposed between the first and the third power supply layers, the first and the third power supply layers respectively comprising at least a power wire, the second metal layer comprising a wire region having at least a wire, the method comprising: selecting a region in the second metal layer exclusive of the wire region, wherein projections of the power wires of the first and the third power supply layers onto the second metal layer in a vertical direction are within the selected region; and disposing a metal plate within the selected region, wherein disposing the metal plate comprising: calculating an area of the selected region; determining whether the area of the selected region is larger than a threshold area; and disposing the metal plate if the area of the selected region is larger than the threshold area; providing vias for coupling the power wires of the first and third power supply layers through the metal plate, so as to reduce an equivalent resistance from a point of the power wire of the first or the third power supply layer to a terminal of a power source, wherein a voltage drop from the point to the terminal after disposing the metal plate is smaller than a voltage drop from the point to the terminal before disposing the metal plate.