SEMICONDUCTOR DEVICE AND SEMICONDUCTOR DEVICE MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor device which includes a MOSFET part and a protection diode part causing avalanche breakdown at a voltage lower than that in the MOSFET part on the same semiconductor substrate, and though having high avalanche resistance, achieves high overvoltage breakdown resistance and high switching speed.SOLUTION: A semiconductor device 100 comprises: a MOSFET part 40 which has first protection trenches 132 each formed deeper than a gate trench 118 and ptype first semiconductor regions 134 each formed on a bottom of the first protection trench 132; and a protection diode part 50 which has second protection trenches 132a each formed deeper than the gate trench 118 and ptype second semiconductor regions 134a each formed on a bottom of the second protection trench 132a. A distance L4 between the neighboring second protection trenches 132a is larger than a distance L3 between the neighboring first protection trenches 132.