Method for manufacturing semiconductor device

A method for manufacturing a semiconductor device, the method comprising:

• providing a dummy gate structure on a semiconductor substrate, wherein the dummy gate structure comprises a dummy gate member, an intermediate layer, and a mask layer, wherein the dummy gate member is positioned between the semiconductor substrate and the intermediate layer, and wherein the intermediate layer is positioned between the dummy gate member and the mask layer;
• providing an insulating structure, such that the dummy gate structure is positioned between two portions of the insulating structure;
• providing an etch-stop material layer that covers both the dummy gate structure and the insulating structure;
• providing a dielectric material layer that covers the etch-stop material layer;
• removing each of the mask layer, a portion of the etch-stop material layer that is positioned above the intermediate layer, and a portion of the dielectric material layer that is positioned above the intermediate layer;
• removing the intermediate layer or a remaining portion of the intermediate layer;
• partially removing a remaining portion of the insulating structure to form a first cavity portion;
• removing the dummy gate member to form a second cavity portion, wherein the second cavity portion is positioned between the semiconductor substrate and the first cavity portion, and wherein a width of the second cavity portion is less than a width of the first cavity portion;
• and
• providing a set of gate metal material through the first cavity portion into the second cavity portion for forming a metal gate member.