SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME

• Main Authors: OKUMURA HIDEKI, KURAGUCHI TOMOMI
• Format: Patent
• Language: English
• Published: 05.09.2013
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PROBLEM TO BE SOLVED: To provide a semiconductor device having a trench gate structure with improved dielectric strength between a gate electrode and a field-plate electrode, and to provide a method of manufacturing the same.SOLUTION: A method of manufacturing a semiconductor device includes the steps of: forming a first insulating film covering inner surfaces of trenches formed in a semiconductor layer and a second insulating film stacked on the first insulating film; forming, at lower portions of the trenches, first control electrodes facing the semiconductor layer via the first insulating film and the second insulating film; forming a third insulating film on the first control electrodes; and removing the first insulating film and the second insulating film formed on wall surfaces at upper portions of the trenches and forming a fourth insulating film. Second control electrodes, which face the semiconductor layer via the fourth insulating film and face the first control electrodes via the third insulating film, are formed at upper portions of the trenches.