Semiconductor device and method of manufacturing semiconductor device

A method of manufacturing a semiconductor device, comprising the steps of:

• (a) forming a first element in a first region of a substrate and a second element in a second region of the substrate;
• (b) forming a first trench in a third region of the substrate and in an outer peripheral region of the second region of the substrate;
• (c) forming an interlayer insulating film over the first element and the second element;
• (d) removing the interlayer insulating film over the first trench in the third region and inside the first trench to form a second trench reaching the substrate;
• (e) forming, in an inner region of the second region, a third trench reaching a component of the second element;
• and
• (f) forming a conductor in the second trench and the third trench,
• wherein the step (f) comprises the following sub-steps of:
• (f1) forming a first conductive film over the bottom surface and side wall of the second and third trenches;
• (f2) forming a second conductive film over the first conductive film;
• (f3) forming a third conductive film over the second conductive film;
• and
• (f4) forming a fourth conductive film over the third conductive film so as to fill the second and third trenches therewith, and
• wherein the step (f2) is a step of forming the first conductive film having a first metal by physical vapor deposition.