| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method for insulation gate type switching element, capable of injecting an impurity into a gate electrode and a semiconductor substrate in the vicinity thereto at a uniform depth and suppressing spread of the injected impurity.SOLUTION: The manufacturing method for insulation gate type switching element includes: a process for forming a trench 40; a process for forming a gate insulation film 42a; a process for depositing an electrode layer 52 formed in the trench 40 and on a surface of a semiconductor substrate 12 by a semiconductor; a process for polishing the electrode layer 52 and exposing a ground layer 42b thereof; a process for forming a cap insulation film 46 on a surface part of the electrode layer 52 in the trench by heat treatment; and a process for injecting impurity. In the process for injecting impurity, an impurity is injected into a range spreading across a semiconductor substrate 12 from the electrode layer 52 in the trench 40, from the surface side of the semiconductor substrate 12.SELECTED DRAWING: Figure 7 |
