Method of manufacturing semiconductor device and semiconductor device

A method of manufacturing a semiconductor device, comprising:

• forming a first low dielectric constant insulating film on a semiconductor substrate;
• etching the first low dielectric constant insulating film so as to pass through the first low dielectric constant insulating film to form a first opening having a first opening width therein, using a first photoresist pattern;
• removing the first photoresist pattern;
• etching the first low dielectric constant insulating film to form a second opening therein, using a second photoresist pattern, the second opening having a second opening width larger than the first opening width and a depth shallower than that of the first opening;
• removing the second photoresist pattern;
• burying a conductive film in a concave portion in which the first and second openings are communicated with each other;
• removing an altered layer formed on a sidewall of the second opening after the conductive film is buried, the altered layer being formed when the second photoresist pattern is removed;
• and
• forming a second low dielectric constant insulating film so as to fill a gap of the sidewall of the second opening therewith, the gap resulting from removing the altered layer.