A memory device includes a page made up of plural memory cells arranged in a column on a substrate, and a page write operation is performed to hold positive hole groups generated by an impact ionization phenomenon, in a channel semiconductor layer by controlling voltages applied to a first gate conductor layer, a second gate conductor layer, a first impurity region, and a second impurity region of each memory cell contained in the page and a page erase operation is performed to remove the positive hole groups out of the channel semiconductor layer by controlling voltages applied to the first gate conductor layer, the second gate conductor layer, the first impurity region, and the second impurity region. The first impurity layer of the memory cell is connected with a source line, the second impurity layer is connected with a bit line, one of the first gate conductor layer and the second gate conductor layer is connected with a word line, and another is connected with a drive control line; during the write operation after the page erase operation, the positive hole group is formed in the channel semiconductor layer by an impact ionization phenomenon by controlling voltages applied to the word line, the drive control line, the source line, and the bit line; and an applied voltage/applied voltages of one or both of the word line and the drive control line is/are lowered with drops in a first threshold voltage of the first gate conductor layer and a second threshold voltage of the second gate conductor layer.

Material layers including first and second poly-Si layer are formed on a P-layer substrate. Holes which are parallel to each other and each of which is continuous in a first direction are formed in the material layers. The first and second poly-Si layers are each divided by the holes in a second direction orthogonal to the first direction in plan view. Gate insulating layers and P-layer Si pillars are formed in the holes. The P-layer Si pillars are isolated from one another by the gate insulating layers. A dynamic flash memory is formed in which a first gate conductor layer is connected to a plate line, a second gate conductor layer is connected to a word line, the P-layer Si pillars serve as channels, and one of the N.sup.+ layers below and above the P-layer Si pillars is connected to a source line.

A P layer 2 having a band shape is on an insulating substrate 1. An N.sup.+ layer 3a connected to a first source line SL1 and an N.sup.+ layer 3b connected to a first bit line are on respective sides of the P layer 2 in a first direction parallel to the insulating substrate. A first gate insulating layer 4a surrounds a portion of the P layer 2 connected to the N.sup.+ layer 3a, and a second gate insulating layer 4b surrounds the P layer 2 connected to the N.sup.+ layer 3b. A first gate conductor layer 5a connected to a first plate line and a second gate conductor layer 5b connected to a second plate line are isolated from each other and cover two respective side surfaces of the first gate insulating layer 4a in a second direction perpendicular to the first direction. A third gate conductor layer 5c connected to a first word line surrounds the second gate insulating layer 4b. These components constitute a dynamic flash memory.

A memory device includes pages containing memory cells arranged in an array on a substrate. In each memory cell, a voltage applied to a first gate conductor layer, second gate conductor layer, third gate conductor layer, first impurity layer, and second impurity layer is controlled to form a hole group by impact ionization inside a channel semiconductor layer, and a page write operation of holding the hole group and a page erase operation of removing the hole group are performed. The first impurity layer is connected to a source line, the second impurity layer to a bit line, the first gate conductor layer to a first plate line, the second gate conductor layer to a second plate line, and the third gate conductor layer to a word line. A page erase operation is performed without inputting a positive or negative bias pulse to the bit line and the source line.

A memory device of the non-volatile type including a memory array having a plurality of memory cells organized as sectors, each sector having a main word line associated with a plurality of local word lines, each local word line coupled to the main word line by a respective local word line driver circuit, each of the local word line driver circuits consisting of a first MOS transistor coupled between the respective main word line and a respective local word line and a second MOS transistor coupled between the respective local word line and a first biasing terminal.

A memory device of the non-volatile type including a memory array having a plurality of memory cells organized as sectors, each sector having a main word line associated with a plurality of local word lines, each local word line coupled to the main word line by a respective local word line driver circuit, each of the local word line driver circuits consisting of a first MOS transistor coupled between the respective main word line and a respective local word line and a second MOS transistor coupled between the respective local word line and a first biasing terminal.

A flash memory lifespan is increased, using a simple process, while restricting an increase in cost. A flash memory management device includes a flash memory having data retaining areas, which retain data, and short-lived areas, which have the same cell structure as the data retaining areas and data retaining properties inferior to those of the data retaining areas, wherein data of the short-lived areas are confirmed by a controller, and data retained in the data retaining areas are refreshed in accordance with the confirmed data of the short-lived areas.

A semiconductor device, the device including: a first silicon layer including first single crystal silicon; an isolation layer disposed over the first silicon layer; a first metal layer disposed over the isolation layer; a second metal layer disposed over the first metal layer; a first level including a plurality of transistors, the first level disposed over the second metal layer, where the isolation layer includes an oxide to oxide bond surface, where the plurality of transistors include a second single crystal silicon region; and a third metal layer disposed over the first level, where a typical first thickness of the third metal layer is at least 50% greater than a typical second thickness of the second metal layer.

A memory device includes a page made up of plural memory cells arranged in a column on a substrate, and a page write operation is performed to hold positive hole groups generated by an impact ionization phenomenon, in a channel semiconductor layer by controlling voltages applied to a first gate conductor layer, a second gate conductor layer, a first impurity region, and a second impurity region of each memory cell contained in the page and a page erase operation is performed to remove the positive hole groups out of the channel semiconductor layer by controlling voltages applied to the first gate conductor layer, the second gate conductor layer, the first impurity region, and the second impurity region. The first impurity layer of the memory cell is connected with a source line, the second impurity layer is connected with a bit line, one of the first gate conductor layer and the second gate conductor layer is connected with a word line, and another is connected with a drive control line. During a refresh operation, at least one of word lines is selected and a voltage of the channel semiconductor layer of the selected word line is returned to a voltage in a state in which a page is written by controlling voltages applied to the selected word line, the drive control line, the source line, and the bit line and thereby forming the positive hole groups by an impact ionization phenomenon in the channel semiconductor layer.

A first impurity layer 101a and a second impurity layer 101b are formed on a substrate Sub at both ends of a Si pillar 100 standing in a vertical direction and having a circular or rectangular horizontal cross-section. Then, a first gate insulating layer 103a and a second gate insulating layer 103b surrounding the Si pillar 100, a first gate conductor layer 104a surrounding the first gate insulating layer 103a, and a second gate conductor layer 104b surrounding the second gate insulating layer 103b are formed. Then, a voltage is applied to the first impurity layer 101a, the second impurity layer 101b, the first gate conductor layer 104a, and the second gate conductor layer 104b to generate an impact ionization phenomenon in a channel region 102 by current flowing between the first impurity layer 101a and the second impurity layer 101b. Of generated electrons and positive holes, the electrons are discharged from the channel region 102 to perform a memory write operation for holding some of the positive holes in the channel region 102, and the positive holes held in the channel region 102 are discharged from one or both of the first impurity layer 101a and the second impurity layer 101b to perform a memory erase operation.