Semiconductor device and method of manufacturing the same

A method of manufacturing a semiconductor device comprising steps of:

• (a) preparing a semiconductor substrate having a first region, a second region, and a third region, the second region and the third region being surrounded by the first region in a plan view;
• (b) forming an annular first insulating film, which surrounds the second region and the third region in a plan view, on the semiconductor substrate in the first region;
• (c) forming a p type semiconductor region in an upper surface of the semiconductor substrate;
• (d) forming a trench in the upper surface of the semiconductor substrate;
• and
• (e) forming a conductive film on the semiconductor substrate including an inside of the trench via a second insulating film and then removing the conductive film outside the trench, thereby forming a gate electrode made of the conductive film in the trench;
• (f) after the (c), forming a resistor element on the second insulating film in the second region via a third insulating film;
• and
• (g) forming a p type semiconductor layer on a lower surface of the semiconductor substrate,
• wherein the gate electrode and the p type semiconductor layer constitute an IGBT,
• wherein the resistor element and the gate electrode are electrically connected to each other, and
• wherein a film thickness of the third insulating film is smaller than a film thickness of the first insulating film and is larger than a film thickness of the second insulating film.