Insulated gate semiconductor device

An insulated gate semiconductor device comprising:

• a carrier transport layer of a first conductivity-type;
• an injection control region of a second conductivity-type on a top surface of the carrier transport layer;
• a carrier supply region of the first conductivity-type selectively at an upper part of the injection control region;
• a base contact region of the second conductivity-type selectively at an upper part of the injection control region;
• a plurality of trenches penetrating the injection control region to reach the carrier transport layer;
• an insulated gate structure inside respective trenches of the plurality of trenches;
• an upper buried region of the second conductivity-type inside the carrier transport layer and in contact with a bottom surface of the injection control region, the upper buried region having side surfaces on both sides of the upper buried region that are in contact with adjacent trenches of the plurality of trenches;
• a lower buried region of the second conductivity-type inside the carrier transport layer and in contact with a bottom surface of the upper buried region and a bottom surface of the respective trenches;
• and
• a high-concentration region of the first conductivity-type inside the carrier transport layer, and in contact with a part of a bottom surface of the lower buried region between the adjacent trenches of the plurality of trenches, the high-concentration region having a higher impurity concentration than the carrier transport layer.

An insulated gate semiconductor device comprising:

• a carrier transport layer of a first conductivity-type;
• an injection control region of a second conductivity-type on a top surface of the carrier transport layer;
• a carrier supply region of the first conductivity-type selectively at an upper part of the injection control region;
• a base contact region of the second conductivity-type selectively at an upper part of the injection control region;
• a plurality of trenches penetrating the injection control region to reach the carrier transport layer;
• an insulated gate structure inside respective trenches of the plurality of trenches;
• an upper buried region of the second conductivity-type inside the carrier transport layer and in contact with a bottom surface of the injection control region;
• a lower buried region of the second conductivity-type inside the carrier transport layer and in contact with a bottom surface of the upper buried region and a bottom surface of the respective trenches;
• and
• a high-concentration region of the first conductivity-type inside the carrier transport layer, and in contact with a part of a bottom surface of the lower buried region between adjacent trenches of the plurality of trenches, the high-concentration region having a higher impurity concentration than the carrier transport layer, wherein
• the adjacent trenches extend in a first direction parallel to each other in a planar pattern,
• the base contact region and the upper buried region are located at positions overlapping with each other intermittently in the first direction, and
• a gap between the positions at which the base contact region and the upper buried region are located differs among a plurality of active areas.

An insulated gate semiconductor device comprising:

• a carrier transport layer of a first conductivity-type;
• an injection control region of a second conductivity-type on a top surface of the carrier transport layer;
• a carrier supply region of the first conductivity-type selectively at an upper part of the injection control region;
• a base contact region of the second conductivity-type selectively at an upper part of the injection control region;
• a plurality of trenches penetrating the injection control region to reach the carrier transport layer;
• an insulated gate structure inside respective trenches of the plurality of trenches;
• an upper buried region of the second conductivity-type inside the carrier transport layer and in contact with a bottom surface of the injection control region;
• a lower buried region of the second conductivity-type inside the carrier transport layer and in contact with a bottom surface of the upper buried region and a bottom surface of the respective trenches;
• and
• a high-concentration region of the first conductivity-type inside the carrier transport layer, and in contact with a part of a bottom surface of the lower buried region between adjacent trenches of the plurality of trenches, the high-concentration region having a higher impurity concentration than the carrier transport layer and a width greater than a width of the base contact region.