Semiconductor device and method of manufacturing the same

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

• (a) preparing a semiconductor substrate having a first semiconductor layer of a first conductivity type and a second semiconductor layer of the first conductivity type formed on the first semiconductor layer;
• (b) forming a gate trench having a predetermined width and reaching an intermediate depth from an upper surface of the second semiconductor layer by using an etching mask having a predetermined opening width;
• (c) forming a first column of the first conductivity type in the second semiconductor layer by introducing an impurity of the first conductivity type into a bottom of the gate trench such that the first column reaches the first semiconductor layer;
• (d) forming a body region of a second conductivity type and a source region of the first conductivity type in the second semiconductor layer at a side surface of the gate trench, the second conductivity type being different from the first conductivity type;
• and
• (e) forming a second column of the first conductivity type in the second semiconductor layer by introducing an impurity of the second conductivity type into the second semiconductor layer such that the second column is spaced from the gate trench and is adjacent to the first column in a first direction along an upper surface of the second semiconductor layer;
• wherein the introduction of the impurity of the first conductivity type in the step (c) is performed by an ion implantation using the etching mask in the step (b) defining an opening of the gate trench.

A semiconductor device comprising:

• a semiconductor substrate having a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type formed on the first semiconductor layer, the second conductivity type being different from the first conductivity type;
• a gate trench having a predetermined width and reaching an intermediate depth from an upper surface of the second semiconductor layer;
• a gate electrode formed in the gate trench via an insulating film;
• a first column of the first conductivity type formed in the second semiconductor layer under a bottom surface of the gate trench and reaching the first semiconductor layer;
• and
• a body region of the second conductivity type and a source region of the first conductivity type formed in the second semiconductor layer on a side surface of the gate trench.