Semiconductor device and method of fabricating the same

A method of fabricating a semiconductor device, comprising steps of:

• forming a groove portion on a main surface of a semiconductor substrate;
• forming an insulating film on a surface of said groove portion;
• forming a gate electrode so as to be in contact with said insulating film in said groove portion;
• and
• forming a source impurity region so as to be adjacent to said groove portion by ion-implanting an impurity into the main surface of said semiconductor substrate, wherein
• said step of forming said gate electrode includes a step of forming said gate electrode such that upper ends of said gate electrode, which are portions in contact with said insulating film, are each located at a position identical with or deeper than the range of said ion-implanted impurity with respect to said insulating film and above a lower surface of said source impurity region.