Kabushiki Kaisha Toshiba

Hideko Oodaira

Kenichi Imamiya

Takashi Mori

Ken Takeuchi

Seiichi Aritome

Kazuhiro Shimizu

Kazuhito Narita

Hiroshi Watanabe

Yuji Takeuchi

Toshitake Yaegashi

Yoshihisa Iwata

Tomoharu Tanaka

Koji Sakui

Yoshiyuki Tanaka

Junichi Miyamoto

Yutaka Okamoto

Hironori Banba

Kazunori Ohuchi

Hiroshi Nakamura

Yasuhisa Takeyama

A semiconductor memory device capable of preventing a defect caused by lowering the etching precision in an end area of the memory cell array is provided. A first block is constructed by first memory cell units each having of memory cells, a second block is constructed by second memory cell units each having memory cells, and the memory cell array is constructed by arranging the first blocks on both end portions thereof and arranging the second blocks on other portions thereof. The structure of the first memory cell unit on the end side of the memory cell array is different from the second memory cell unit. Wirings for connecting the selection gate lines of the memory cell array to corresponding transistors in a row decoder are formed of wiring layers formed above wirings for connecting control gate lines of the memory cell array to the transistors in the row decoder.

Semiconductor memory device capable of realizing a chip with high operation reliability and high yield

A select gate transistor has a select gate electrode composed of a first-level conductive layer and a second-level conductive layer. The first-level conductive layer has contact areas. The second-level conductive layer has its portions removed that are located above the contact areas. Two adjacent select gate electrodes that are adjacent to each other in the column direction are arranged such that the contact areas of one select gate electrode are not opposed to the contact areas of the other select gate electrode. One select gate electrode has its first- and second-level conductive layers removed in their portions that are opposed to the contact areas of the other select gate electrode.

Nonvolatile semiconductor memory

A semiconductor memory device capable of preventing a defect caused by lowering the etching precision in an end area of the memory cell array is provided. A first block is constructed by first memory cell units each having of memory cells, a second block is constructed by second memory cell units each having a plurality of memory cells, and the memory cell array is constructed by arranging the first blocks on both end portions thereof and arranging the second blocks on other portions thereof. The structure of the first memory cell unit on the end side of the memory cell array is different from that of the second memory cell unit. Wirings for connecting the selection gate lines of the memory cell array to corresponding transistors in a row decoder are formed of wiring layers formed above wirings for connecting control gate lines of the memory cell array to the transistors in the row decoder.

A semiconductor memory device capable of preventing occurrence of a defect caused by a lowering in the etching precision in an end area of the memory cell array and realizing an inexpensive chip having high operation reliability and high manufacturing yield is provided. A first block is constructed by first memory cell units each having a plurality of memory cells connected, a second block is constructed by second memory cell units each having a plurality of memory cells connected, and the memory cell array is constructed by arranging the first blocks on both end portions thereof and arranging the second blocks on other portions thereof. The structure of the first memory cell unit on the end side of the memory cell array is different from that of the second memory cell unit. Wirings for connecting the selection gate lines of the memory cell array to corresponding transistors in a row decoder are formed of wiring layers formed above wirings for connecting control gate lines of the memory cell array to the transistors in the row decoder. By use of the semiconductor memory device, occurrence of a defect caused by a lowering in the etching precision in an end area of the memory cell array can be prevented, and the manufacturing yield can be made high and the operation reliability can be made high without substantially increasing the chip size.

A select gate transistor has a select gate electrode composed of a first-level conductive layer and a second-level conductive layer. The first-level conductive layer has a plurality of contact areas. The second-level conductive layer has its portions removed that are located above the contact areas. Two adjacent select gate electrodes that are adjacent to each other in the column direction are arranged such that the contact areas of one select gate electrode are not opposed to the contact areas of the other select gate electrode. One select gate electrode has its first- and second-level conductive layers removed in their portions that are opposed to the contact areas of the other select gate electrode.

A semiconductor memory device includes a memory cell array comprising memory cell units arranged in an array form, first blocks including first memory cell units each having at least one memory cell and at least one selection gate transistor, and second blocks including second memory cell units each having at least one memory cell and at least one selection gate transistor, wherein the first blocks are arranged on both end portions of the memory cell array, the second blocks are arranged in another portion, and a structure of the first memory cell units on the end portions of the memory cell array is different from a structure of the second memory cell units.

Growing community of inventors

Kuroishi, Japan

Hideko Oodaira