Insulated gate bipolar transistor

An Insulated Gate Bipolar Transistor comprising:

• a first conductivity type first semiconductor layer having first and second major surfaces;
• a second conductivity type second semiconductor layer formed on said first major surface;
• a first conductivity type third semiconductor layer selectively formed in a surface of said second semiconductor layer which is opposite to said first semiconductor layer;
• a second conductivity type fourth semiconductor layer selectively formed in a surface of said third semiconductor layer;
• a groove extending from said second major surface to said second semiconductor layer;
• an insulative layer formed on part of said surface of said third semiconductor layer which is between said second and fourth semiconductor layers;
• a control electrode formed in said insulative layer;
• a first electrode formed over said third and fourth semiconductor layers;
• a second conductivity type fifth semiconductor layer, a first conductivity type sixth semiconductor layer and a second conductivity type seventh semiconductor layer of impurity concentration higher than that of said second semiconductor layer, which are stacked in order from inside of said groove;
• and
• a second electrode formed for connection to said first semiconductor layer on said second major surface and to said fifth and sixth semiconductor layers.