US Patent 10886224 Power distribution network using buried power rail

A tap cell configured to enable electrical connection from a buried power rail of an integrated circuit to a power distribution network includes. The tap cell includes a buried power rail layer including VDD and VSS power supply lines, insulating layers and metal layers alternately arranged on the buried power rail layer, a first power supply interconnect in metal layer M1 or higher electrically coupled to the VDD power supply line, and a second power supply interconnect in metal layer M1 or higher electrically connected to the VSS power supply line. The first power supply interconnect and the second power supply interconnect are configured to be electrically connected to the power distribution network, and the VDD and VSS power supply lines are configured to supply power from the power distribution network to the buried power rail of the integrated circuit. The tap cell is free of any active semiconductor devices.