Provided is a method for manufacturing a p-type MOSFET, including: forming a part of the MOSFET on a semiconductor substrate including source/drain regions, a replacement gate, and a gate spacer; removing the replacement gate stack of the MOSFET to form a gate opening; forming an interface oxide layer on the exposed surface of the semiconductor substrate; forming a high-K gate dielectric layer on the interface oxide layer; forming a first metal gate layer; implanting dopant ions into the first metal gate layer; and performing annealing to cause the dopant ions to diffuse and accumulate at an upper interface between the high K gate dielectric layer and the first metal gate layer and a lower interface between the high-K gate dielectric layer and the interface oxide layer, and also to generate electric dipoles by interfacial reaction at the lower interface between the high-K gate dielectric layer and the interface oxide layer.