Kabushiki Kaisha Toshiba

Ryuichi Kamo

Hiroaki Tsunoda

Minori Kajimoto

Yuuichiro Murahama

Tadashi Iguchi

Hisashi Watanobe

A semiconductor device such as a flash memory includes a semiconductor substrate, two gate insulating films formed on the substrate so as to have a first film thickness and a second film thickness smaller than the first film thickness respectively, and a polycrystalline silicon film formed on the gate insulating films so that parts of the polycrystalline silicon film on the respective gate insulating films are on a level with each other and serving as a gate electrode. The substrate is formed with a recess defined by a bottom and sidewalls substantially perpendicular to the bottom, the recess corresponding to the part of the gate insulating film with the first film thickness.

Semiconductor device and method of fabricating the same

A semiconductor device includes a semiconductor substrate including a plurality of trenches formed along a first direction and a plurality of first upper surfaces divided by the trenches, a plurality of element isolation insulating films embedded in the respective trenches and including a plurality of second upper surfaces continuous with the first upper surfaces in a second direction which is perpendicular to the first direction, respectively, a plurality of interlayer insulating films formed above the first and the second upper surfaces, and a plurality of contact plugs defined in the interlayer insulating films so as to connect with the first upper surfaces of the semiconductor substrate. Each first upper surface is inclined in the second direction so as to be lowered from a central part toward interfaces between each first upper surface and the second upper surfaces adjacent to each first upper surface.

Semiconductor device with trench isolation

Semiconductor device and method for fabricating the same

A semiconductor device includes a semiconductor substrate including a first upper surface, a first insulating film including an upper portion including a first side wall having a first upper end and a second upper surface having a second upper end, a second insulating film formed on the first upper surface of the substrate, a floating gate electrode including a third upper surface, a second side wall and a lower surface, a third insulating film, and a control gate electrode. A height of the second upper end is lower than a height of the third upper surface and higher than a height of the first upper end relative to the first upper surface. The first upper end is located at a position higher than the lower surface of the floating gate electrode. The entire second side wall is aligned with the first side wall of the first insulating film.

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Yokkaichi, Japan

Ryuichi Kamo