Power rail design method, apparatus and non-transitory computer readable medium thereof

A power rail design method is disclosed that includes the steps outlined below. A plurality of power rails and a plurality of power domains corresponding thereto in a semiconductor circuit design file are identified. A design rule check of a plurality of circuit cells being placed and routed in the semiconductor circuit design file is performed to retrieve a plurality of non-violation circuit regions that correspond to the power rails of each of the power domains. The power rails of the semiconductor circuit design file are widened to occupy at least part of the non-violation circuit regions.