Semiconductor integrated circuit device and method for designing layout of the same

A semiconductor integrated circuit device including a semiconductor substrate having a logic circuit placement region, the semiconductor integrated circuit device comprising:

• a plurality of standard cells that are placed in a part of the logic circuit placement region and respectively constitute a plurality of functional blocks that realize logic functions of the semiconductor integrated circuit device;
• a plurality of basic cells that are placed in a part of regions of the logic circuit placement region in which no standard cells are placed;
• and
• at least one diode cell that is placed in at least a part of regions of the logic circuit placement region in which no standard cells and no basic cells are placed, the diode cell including a first diode that is connected between a gate electrode of a predetermined transistor and a first power supply line and a second diode that is connected between the gate electrode and a second power supply line,
• wherein the diode cell is placed, in a direction that is orthogonal to a longitudinal direction of the diode cell, in at least a part of regions between two adjacent standard cells, regions between a standard cell and a basic cell, or regions at an end portion of the logic circuit placement region.