Semiconductor device having a trench gate structure

摘要

A U-IGBT of the present invention has a trench gate structure comprising gate electrodes (15) embedded in trenches (10) formed on a major surface of a semiconductor substrate (11), using sidewalls of each of the trenches as a channel region. The U-IGBT has a source region (13) comprising first sections (13A) and second sections (13B). The first sections (13A) are formed in a first direction parallel to the longitudinal direction of the trench gate electrodes (15). The second sections (13B) are formed with a predetermined interval in a second direction perpendicular to the longitudinal direction of the trench gate electrodes (15) and connect neighboring first sections (13A) that are sandwiched by neighboring trench gate electrodes (15). The U-IGBT has a surface emitter electrode (17) formed so as to contact both the second sections (13B) of the source region (13) and a base region (12) adjoining thereto. The width of a second section (13B) in the source region (13) is two thirds or less of a cell pitch (P). The sum of the width of a second section (13B) in the source region (13) and the width of a base region (12) adjoining to the above second section (13B) is three times or less as large as the cell pitch (P).