Mitsubishi Electric Corporation

Ryoichi Fujii

Atsushi Narazaki

Kaoru Motonami

Shigeto Honda

Yoichiro Tarui

Kazunari Nakata

Tomoya Hirata

Ayumu Onoyama

A semiconductor device using one or more guard rings includes a p-type guard ring region surrounding a pn junction region, an insulating film covering the p-type guard ring region, one or more conductive films electrically connected with the p-type guard ring region through one or more contact holes made in the insulating film, and a semi-insulating film covering the insulating film and the conductive films. Thus, a desired breakdown voltage characteristic can be ensured even if a foreign matter or the like adheres to a surface of the conductive films.

Semiconductor device

A method of manufacturing a power semiconductor device according to the present invention includes the steps of: (a) forming a silicon nitride film on a semiconductor substrate; (b) after the step (a), forming a ring-shaped trench along a peripheral portion of the semiconductor substrate; (c) forming a first silicon oxide film on an inner surface of the trench; (d) after the step (c), forming a second silicon oxide film on an entire surface of the semiconductor substrate to bury the trench; (e) planarizing the second silicon oxide film by using the silicon nitride film as a stopper; and (f) forming a third silicon oxide film in a region in which the silicon nitride film is removed.

Power semiconductor device and method of manufacturing the same

A passivation film having a predetermined width from an outer peripheral end portion toward an inner side and extending along the outer peripheral end portion is formed on a front surface of a semiconductor substrate. An outer peripheral end surface orthogonal to the front surface and a rear surface is formed by grinding the outer peripheral end portion of the semiconductor substrate. A thickness of the semiconductor substrate is reduced to a predetermined thickness by grinding the rear surface. The ground rear surface is etched by discharging a mixed acid onto the rear surface while rotating the semiconductor substrate with the rear surface facing upward, to remove a fracture layer. Thereby, chipping or cracking of the semiconductor substrate is suppressed.

Method of manufacturing semiconductor device

Growing community of inventors

Chiyoda-ku, Japan

Ryoichi Fujii