SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SAME

摘要

According to one embodiment, a method for manufacturing a semiconductor device includes: forming a plurality of trenches; forming a gate insulating film; burying a gate electrode; burying an insulating member; projecting the insulating member; forming a base layer; forming a mask film; forming a first semiconductor layer; forming a carrier ejection layer; forming a first electrode; and forming a second electrode. The projecting includes projecting the insulating member from the upper surface of the semiconductor substrate by removing an upper layer portion of the semiconductor substrate. The mask film is formed so as to cover the projected insulating member. The forming the first semiconductor layer includes forming a first semiconductor layer of the first conductivity type in an upper layer portion of the base layer by doping the base layer with impurity, the upper layer portion having a lower surface below an upper end of the gate electrode.

主权项

1. A method for manufacturing a semiconductor device, comprising:
forming a plurality of trenches in an upper surface of a semiconductor substrate of a first conductivity type; forming a gate insulating film on an inner surface of the trench; burying a gate electrode in a lower portion in the trench; burying an insulating member in an upper portion in the trench; projecting the insulating member from the upper surface of the semiconductor substrate by removing an upper layer portion of the semiconductor substrate; forming a base layer of a second conductivity type in a portion of the semiconductor substrate above a lower end of the gate electrode by doping the semiconductor substrate with impurity; forming a mask film so as to cover the projected insulating member; forming a first semiconductor layer of the first conductivity type in an upper layer portion of the base layer by doping the base layer with impurity, the upper layer portion having a lower surface below an upper end of the gate electrode; forming a carrier ejection layer of the second conductivity type in part of the base layer and part of the first semiconductor layer by implanting impurity into the semiconductor substrate using a portion of the mask film formed on a side surface of the insulating member as a mask, the carrier ejection layer having a higher effective impurity concentration than the base layer; forming a first electrode so as to be connected to the upper surface of the semiconductor substrate; and forming a second electrode so as to be connected to a lower surface of the semiconductor substrate.