Trench vertical power MOSFET with channel including regions with different concentrations

• Main Authors: Katou, Hiroaki, Kishimoto, Hiroyuki
• Format: Patent
• Language: English
• Published: 11.04.2023
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A semiconductor device includes: a first semiconductor layer of first conductivity type; a second semiconductor layer of first conductivity type provided on the first semiconductor layer; a first semiconductor region of second conductivity type provided on the second semiconductor layer; a second semiconductor region of first conductivity type provided on the first semiconductor region; a first electrode provided in a first trench, the first trench reaching the second semiconductor layer from above the first semiconductor region, the first electrode facing the first semiconductor region via a first insulating film; a second electrode provided in a second trench, the second trench reaching the second semiconductor layer from above the first semiconductor region, the second electrode facing the first semiconductor region via a second insulating film; a third electrode including a first electrode portion, a second electrode portion provided on the first electrode portion and a third electrode portion provided on the second electrode portion, the first electrode portion being provided between the first trench and the second trench, the first electrode portion reaching the first semiconductor region from above the second semiconductor region, the first electrode portion being electrically connected to the first semiconductor region and the second semiconductor region; a third semiconductor region provided between the third electrode and the second semiconductor region provided between the first insulating film and the third electrode, the third semiconductor region having a higher concentration of impurities of second conductivity type than the first semiconductor region; a fourth semiconductor region provided between the third electrode and the second semiconductor region provided between the second insulating film and the third electrode, the fourth semiconductor region having a higher concentration of impurities of second conductivity type than the first semiconductor region; and a fifth semiconductor region provided between the first semiconductor region and the third electrode, the fifth semiconductor region being provided apart from the third semiconductor region and the fourth semiconductor region, the fifth semiconductor region having a higher concentration of impurities of second conductivity type than the first semiconductor region.