Kabushiki Kaisha Toshiba

Daisuke Tohyama

Junichiro Noda

Masataka Takebuchi

Hidemitsu Ogura

A select MOS transistor and a data storage MOS transistor are formed in an element region. The transistor has floating-gate electrodes. The floating-gate electrodes are spaced apart above the element region and connected to each other above a field region. Only a tunnel insulating film much thinner than a gate insulating film of the transistor is placed between the floating-gate electrode and a drain region. Only the gate insulating film much thinner than the gate insulating film of the transistor is placed between the floating-gate electrode and the channel region of the transistor. In the element region, the shape of a control electrode is the same as that of the floating-gate electrodes.

Nonvolatile semiconductor memory device

Method of manufacturing a semiconductor memory device

According to this invention, a semiconductor non-volatile memory device includes a semiconductor substrate, insulating films formed on the semiconductor substrate and having at least two types of gate insulating films having different thicknesses and a first conductive film formed on the insulating films and electrically floating from the semiconductor substrate through the insulating films. These at least two types of gate insulating films include a first insulating film formed on said semiconductor substrate and a first diffusion layer of a conductivity type and a second insulating film formed on said semiconductor substrate and a second diffusion layer, of the opposite conductivity type, which is isolated from the first diffusion layer. The first conductive film is formed on the first and second insulating films. A part of the first insulating film between the first conductive film and the first diffusion layer is constituted by a third insulating film having a thickness smaller than that of the first insulating film.

Growing community of inventors

Kawasaki, Japan

Daisuke Tohyama