Fujitsu Semiconductor Limited

Fujitsu Corporation

Mie Fujitsu Semiconductor Limited

United Semiconductor Japan Co., Ltd.

Satoshi Torii

Hiroshi Mawatari

Kazuhiro Mizutani

Masayoshi Asano

Toshio Nomura

Ikuto Fukuoka

Motoi Takahashi

Tatsuya Sugimachi

Hideaki Matsumura

Shu Ishihara

Hideyuki Kojima

Hikaru Kokura

Katsuaki Ookoshi

Kengo Inoue

Yuka Kase

Junichi Ariyoshi

Etsuro Kawaguchi

A nonvolatile semiconductor memory device includes a selection transistor and a memory transistor that are formed on a well for each of a plurality of memory cells. At a time of a data read from the memory transistor, a first voltage is applied to the well and a source of the memory transistor, and a second voltage is applied to a gate of the selection transistor included in a non-selected memory cell among the plurality of memory cells. The first voltage is smaller than an absolute value of the second voltage.

Nonvolatile semiconductor memory device

A manufacturing method of a semiconductor device includes: forming a tunnel oxide layer and a charge-storage layer in a region of a flash memory transistor; forming a first oxide film; removing the first oxide film in regions of a first transistor and a second transistor; forming a third oxide film by adding a first oxide layer between a first oxide film and a semiconductor substrate in a region of a third transistor while forming a second oxide film in the regions of the first transistor and the second transistor by oxidation; removing the second oxide film in the region of the first transistor; and forming a fifth oxide film by adding a second oxide layer between the second oxide film and the semiconductor substrate in the region of the second transistor while forming a fourth oxide film in the region of the first transistor by oxidation, and forming a sixth oxide film by adding a third oxide layer between the first oxide layer and the semiconductor substrate in the region of the third transistor.

Manufacturing method of semiconductor device

A semiconductor storage device including plural bit lines, plural select gate lines that intersect with the plural bit lines, and plural memory cells that each include a p-channel memory transistor. The semiconductor storage device includes plural p-channel charging transistors that are respectively connected to the plural bit lines, and a charging line that is connected to each of the plurality of charging transistors. A controller that ON/OFF controls the charging transistors places each of the charging transistors in an ON state prior to read current flowing in a read target bit line, and that places the charging transistor connected to the read target bit line in an OFF state when read current flows in the read target bit line.

Semiconductor storage device and data read method

A semiconductor device manufacturing method includes: forming an element isolation insulating film in a semiconductor substrate; forming a first film on a surface of the semiconductor substrate; forming a second film on the element isolation insulating film and on the first film; forming a first resist pattern that includes a first open above the element isolation insulating film in a first region; removing the second film on the element isolation insulating film in the first region to separate the second film in the first region into a plurality of parts by performing first etching; forming a third film on the second film in the first region; forming a first gate electrode on the third film in the first region; and forming a first insulating film that includes the first to third films under the first gate electrode by patterning the first to third films.

Semiconductor device manufacturing method and semiconductor device

A semiconductor device includes: a memory cell transistor which has a floating gate, a control gate, and a source and a drain formed in a semiconductor substrate on both sides of the floating gate via a channel area; and a selecting transistor which has a select gate and a source and a drain formed in the semiconductor substrate on both sides of the select gate, wherein the source of the selecting transistor is connected to the drain of the memory cell transistor, the source of the memory cell transistor has an N-type first impurity diffusion layer, an N-type second impurity diffusion layer deeper than the first impurity diffusion layer, and an N-type third impurity diffusion layer which is shallower than the second impurity diffusion layer, and an impurity density of the second impurity diffusion layer is lower than that of the third impurity diffusion layer.

Semiconductor device and fabricating method thereof

A method of manufacturing a semiconductor device includes: forming a conductive film on a semiconductor substrate; patterning the conductive film in a memory region to form a first gate electrode; after forming the first gate electrode, forming a mask film above each of the conductive film in a logic region and the first gate electrode; removing the mask film in the logic region; forming a first resist film above the mask film left in the memory region and above the conductive film left in the logic region; and forming a second gate electrode in the logic region by etching the conductive film using the first resist film as a mask.

Method of manufacturing semiconductor device

Local bit lines (LBL) are respectively provided for a plurality of sectors, corresponding to each of the global bit lines (GBL). Sector select transistors connect a LBL to a GBLector select lines control the on/off state of the sector select transistors for the corresponding sectors. A plurality of word lines (WL) intersect the local bit lines. Memory cells are located at the intersections between the LBL and the WL. Each memory cell connects a source line with the corresponding LBL and includes an n-channel transistor that is turned on/off by the corresponding WL. A precharge voltage is applied to a charging line. Charging transistors connect the LBL to the charging line. A charging gate line controls the on/off state of the charging transistors.

Non-volatile semiconductor memory with bit line hierarchy

A nonvolatile semiconductor memory device including a first bit line commonly coupling drain sides memory cells; a word line commonly coupling control gates of memory cell transistors; a column decoder coupled to a second bit line; a row decoder coupled to a word line; a first transistor having a source coupled to the first bit line and having a drain electrically coupled to the column decoder via the second bit line; and a first control unit for controlling potential of a gate of the first transistor, the memory cell transistor being formed over a first well, the first transistor being formed over a second well electrically isolated from the first well, a film thickness of a gate insulation film of the first transistor being smaller than that of a gate insulation film of a second transistor formed in the row decoder and coupled to the word line.

Nonvolatile semiconductor memory device and erasing method of nonvolatile semiconductor memory device

A nonvolatile semiconductor memory device including a memory cell array of memory cells arranged in a matrix, each of which includes a selecting transistor and a memory cell transistor; a column decoder controlling the potential of bit lines; a voltage application circuit controlling the potential of the first word lines; a first row decoder controlling the potential of the second word lines; and a second row decoder controlling the potential of the source line. The column decoder is formed of a circuit whose withstand voltage is lower than the voltage application circuit and the second row decoder.

A semiconductor memory device includes a plurality of memory cell transistors arranged in a matrix; a plurality of word lines commonly coupling the control gates of the plural memory cell transistors present in a identical first direction; a plurality of source lines commonly coupling the sources of the plural memory cell transistors present in the identical first direction; a plurality of bit lines commonly coupling the drains of the plural memory cell transistors present in a identical second direction intersecting the first direction; a first transistor having a drain coupled to the source line; a second transistor having a drain coupled to a source of the first transistor, a gate coupled to the word line and a source grounded; and a control line commonly coupling the gates of the plural first transistors.

Semiconductor memory device and method for driving semiconductor memory device

A nonvolatile semiconductor memory including a memory cell array of memory cells arranged in a matrix, each of which includes a selective transistor and a memory cell transistor; the first column decoder for controlling the potentials of the bit lines and the source lines; the first row decoder for controlling the potential of the first word lines; the second row decoder for controlling the potential of the second word lines; and the second column decoder. The first column decoder includes a circuit whose withstand voltage is lower than the first row decoder and the second column decoder, and the second row decoder includes a circuit whose withstand voltage is lower than the first row decoder and the second column decoder.

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Kuwana, Japan

Satoshi Torii