A method of manufacturing a dynamic random access memory is provided and includes: forming a hard mask layer on a substrate; forming an opening in the hard mask layer and the substrate; forming a dielectric layer on a sidewall of the opening; forming a first part of a buried word line in a lower part of the opening; forming a hard mask layer on a top surface of the hindering layer, where the hindering layer has overhangs covering top corners of the hard mask layer; depositing a first barrier layer on the substrate through hindrance of the overhangs, where the first barrier layer covers the hindering layer and a top surface of the first part and exposes the dielectric layer on the sidewall of the opening; and forming a first conductive layer in the opening, where a sidewall of the first conductive layer contacts the dielectric layer.