Kabushiki Kaisha Toshiba

Wakako Moriyama

Hiroaki Hazama

Riichiro Shirota

Seiichi Aritome

Kazuhiro Shimizu

Akira Goda

Hirohisa Iizuka

Yoshio Ozawa

Yuji Fukazawa

Yasumasa Suizu

Kazuo Saki

Naoki Kai

Keiki Nagai

A method for manufacturing a nonvolatile semiconductor memory device having a step of forming a first gate electrode on a peripheral circuit portion and a second gate electrode on a memory cell portion, a step of introducing impurity into the peripheral circuit portion and memory cell portion, a step of forming a first insulating film above at least the memory cell portion, and a step of annealing the semiconductor substrate into which the impurity has been introduced. The first gate electrode has a first gate length. The second gate electrode has a second gate length shorter than the first gate length.

Nonvolatile semiconductor memory device and method for manufacturing the same

A nonvolatile semiconductor memory device includes erasable and programmable memory cell transistors, a selection transistor, a peripheral transistor, first post-oxidation films each provided on a gate electrode of all of the plurality of erasable and programmable memory cell transistors, a second post-oxidation film provided on a gate electrode of the selection transistor, a third post-oxidation film provided on a gate electrode of the peripheral transistor, and an insulating film covering the memory cell transistors, the selection transistor, and the peripheral transistor. The insulating film is harder for an oxidizing agent to pass through than a silicon oxide film. The insulating film has an oxidized region. The insulating film includes a silicon nitride film. The oxidized region is provided in a surface of the silicon nitride film.

A nonvolatile semiconductor memory device includes comprises: an element isolation region being in contact with a first element region, an insulating film covering a memory cell, a peripheral transistor and the element isolation region, an inter-level insulating film provided on the surface of the insulating film, and a contact hole provided in the inter-level insulating film and the insulating film. The inter-level insulating film contains an insulator different from the insulating film. The contact hole reaches at least one of source and drain diffusion layers of the memory cell and overlaps the element isolation region. The insulating film contains an insulator different from the element isolation region and the insulating film is harder for an oxidizing agent to pass therethrough than a silicon oxide film. A surface of the insulating film is oxidized.

Nonvolatile semiconductor memory device covered with insulating film which is hard for an oxidizing agent to pass therethrough

A thermal nitride film is formed as a gate insulating film on a silicon substrate, and after a gate electrode material is formed on the insulating film, it is patterned to form gate electrodes. After processing the electrodes, part of the gate insulating film other than a portion thereof which lies under the gate electrodes is removed. Further, an insulating film (a post oxidation film) is formed on side walls and upper surfaces of the stacked gate structures and the exposed main surface of the silicon substrate by use of thermal oxidation method.

Method for manufacturing semiconductor devices using thermal nitride films as gate insulating films

A nonvolatile semiconductor memory device includes memory cell transistors, peripheral transistors, first post-oxidation films provided on the gate electrode of all of the memory cell transistors, second post-oxidation films provided on the gate electrode of all of the peripheral transistors, first insulating films provided on the first post-oxidation films and covering a side surface of the gate electrode of all of the memory cell transistors and second insulating films provided on the second post-oxidation films and covering a side surface of the gate electrode of all of the peripheral transistors. The first and second insulating films are harder for an oxidizing agent to pass therethrough than a silicon oxide film, and the first and second insulating films are oxidized.

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Yokohama, Japan

Wakako Moriyama