Kabushiki Kaisha Toshiba

Tomomi Kusaka

Takashi Izumida

Nobutoshi Aoki

Masaki Kondo

Takahisa Kanemura

Noboru Ooike

In one embodiment, a nonvolatile semiconductor memory device includes a substrate, and a well region formed in the substrate. The device further includes device regions formed in the well region and defined by isolation trenches formed in the well region, the device regions extending in a first direction parallel to a principal surface of the substrate, and being adjacent to one another in a second direction that is perpendicular to the first direction. The device further includes isolation insulators buried in the isolation trenches to isolate the device regions from one another. The device further includes floating gates disposed on the device regions via gate insulators, and a control gate disposed on the floating gates via an intergate insulator. The device further includes first diffusion suppressing layers formed inside the respective device regions to divide each of the device regions into an upper device region and a lower device region. The device further includes second diffusion suppressing layers formed on side surfaces of the respective upper device regions, the side surfaces being perpendicular to the second direction.

Nonvolatile semiconductor memory device and method of manufacturing the same

A semiconductor memory device according to an embodiment of the present invention includes a substrate, a first gate insulator formed on the substrate and serving as an F-N (Fowler-Nordheim) tunneling film, a first floating gate formed on the first gate insulator, a second gate insulator formed on the first floating gate and serving as an F-N tunneling film, a second floating gate formed on the second gate insulator, an intergate insulator formed on the second floating gate and serving as a charge blocking film, and a control gate formed on the intergate insulator, at least one of the first and second floating gates including a metal layer.

Semiconductor memory device

A semiconductor memory device according to an embodiment of the present invention includes a substrate, a gate insulator formed on the substrate and serving as an F-N (Fowler-Nordheim) tunneling film, a first floating gate formed on the gate insulator, a first intergate insulator formed on the first floating gate and serving as an F-N tunneling film, a second floating gate formed on the first intergate insulator, a second intergate insulator formed on the second floating gate and serving as a charge blocking film, and a control gate formed on the second intergate insulator.

A process simulation method includes: converting condition data of plasma doping for introducing an impurity into a semiconductor in a plasma atmosphere to corresponding condition data of ion implantation for implanting impurities as an ion beam into the semiconductor; and calculating device structure data on the basis of the ion implantation condition data converted from the plasma doping condition data.

Growing community of inventors

Yokohama, Japan

Tomomi Kusaka