TRENCH-GATE TYPE SEMICONDUCTOR DEVICE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To eliminate a malfunction caused by cracks starting from an interlayer insulating film at the timing of bonding. SOLUTION: A plurality of trenches 5 are formed on the top surface of a semiconductor substrate 1, and the trenches 5 pass through a p-base layer 4 and reach an n<-> -type drift layer 3. A recessed part 6 is formed on the top opening portion of the trench 5. A gate insulating film 7 is formed on the inside wall surface of the trench 5 and a gate electrode 8 is formed inside the gate insulating film 7. A high concentration n<+> -emitter layer 10 is selectively formed at the boundary of the p-base layer 4 and the recessed part 6. An interlayer insulating film 9 is formed so as to bury the recessed part 6 to make the top surfaces of the p-base layer 4, the n<+> -emitter layer 10 and the substrate 1 nearly flat. An emitter electrode 11 is formed such that it contacts the p-base layer 4 and the n<+> -emitter layer 10. A collector electrode 13 is formed on the bottom surface of a p<+> -substrate 2.