Trench gate power switch with doped regions to induce breakdown at selected areas

An insulated trench gate device formed in a die comprising:

• active cells in an active area of the device;
• inactive cells in an active area perimeter surrounding the active area;
• a termination region between the active area perimeter and an edge of the die;
• a first layer of a first conductivity type, the first layer having a first concentration of dopants of the first conductivity type;
• trenches formed in the first layer;
• a gate oxide along sidewalls of the trenches;
• a first conductive material at least partially filling the trenches to form gates;
• first regions of a second conductivity type adjacent to and near tops of at least some of the trenches in the active area of the device;
• a top first electrode electrically contacting the first regions;
• a second layer of the second conductivity type below the first layer;
• and
• second regions of the first conductivity type formed in the first layer that extend below the trenches in the active area perimeter, the second regions being electrically connected to the first electrode, the second regions having a second dopant concentration that is higher than the first dopant concentration.