| 摘要 |
PROBLEM TO BE SOLVED: To improve OFF characteristic and ON characteristic by improving current ability while realizing high withstand voltage in a trench gate type IGBT. SOLUTION: A channel layer 26 and a high concentration n-type region 27 are formed on a high concentration p-type substrate 23 by using a substrate wherein a high concentration n-type epitaxial layer 24 and a low concentration n-type epitaxial layer 25 are stacked, and a trench 29 is formed to pass through the layers. After a gate insulating film 30 is formed, it is charged with polycrystalline silicon and a trench gate electrode 31 is formed. A depth size (b) of the trench gate electrode 31 is made shallower than a depth size (a) of a deepest part of the channel layer 26. As a result, it is possible to improve withstand voltage by preventing field concentration in a bottom of the trench gate electrode 31 and to improve current ability.
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