Abstract: A nonvolatile semiconductor memory device is provided which includes a plurality of memory cells each having a floating gate, wherein a threshold level of each memory cell depends on a value of electric charge in said floating gate of said memory cell, and wherein said threshold level of each memory cell is placed at one of a first area and a second area. A controller is also provided which controls to set each threshold voltage of selected ones of said plurality of memory cells, wherein said controller performs a first setting operation and a verifying operation. The first setting operation shifts threshold voltages of the selected ones of said plurality of memory cells in a direction from said first area to said second area. The verifying operation detects erratic memory cells which have threshold voltages which are on a side of said second area which is opposite of a middle area formed between the first area and the second area.

Abstract: Respective nodes N1 to N3 only detect a carrier, and the node N3 sets a random time between a time after a certain period of time t1 and a time until a certain period of time t2 after the carrier of data D11 is gone as a waiting time so as to transmit data within this waiting time. The node N1 transmits ACK data D12 with respect to the data D11 to the node N12 before the certain period of time t1 after the carrier of the data D11 is gone. The node N3 detects the carrier of the ACK data D12 and again sets a random time after the certain period of time t1 until the certain period of time t2 to transmit the data.

Abstract: A gate electrode of a field-effect transistor used as a peripheral circuit is constituted by the same gate electrode structure as a double-level gate electrode structure of nonvolatile memory cells, and a contact hole for connecting those conductive films constituting the gate electrode is provided at a location which two-dimensionally overlaps an active area within a plane of the gate electrode. A hole for connecting between the two layers of the gate electrode of a first field-effect transistor used as perpheral circuit is provided at a location which two-dimensionally overlaps the active area within the plane of the gate electrode, and a hole for connecting between the two layers of the gate electrode of a second field-effect transistor used as a peripheral circuit is provided at a location which two-dimensionally overlaps an isolation area within the plane of the gate electrode.

Abstract: A gate electrode of a field-effect transistor used as a peripheral circuit is constituted by the same gate electrode structure as a double-level gate electrode structure of nonvolatile memory cells. A hole for connecting the two layers of the gate electrode of a first field-effect transistor used as peripheral circuit is provided at a location which two-dimensionally overlaps the active area within the plane of the gate electrode, and a hole for connecting the two layers of the gate electrode of a second field-effect transistor used as a peripheral circuit is provided at a location which two-dimensionally overlaps an isolation area within the plane of the gate electrode. The gate length of the first field-effect transistor is longer than the gate length of the second field-effect transistor, and the gate width of the first field-effect transistor is wider than the gate width of the second field-effect transistor.

Abstract: A method of manufacturing a nonvolatile semiconductor memory device which is protected against deterioration in the electron injection/discharge characteristics between a floating gate of a memory cell and a channel. Three layers including a gate oxide film, a first polysilicon layer and a first nitride film are sequentially deposited on a silicon substrate surface and patterned with stripe-like columnwise lines. A second nitride film is formed on side walls of the columnwise lines, respectively. An element isolating insulation film is formed on the silicon substrate surface which is not covered with the first and second nitride films. After removal of the first and second nitride films, a first insulation film is formed on the side walls of the first polysilicon layer.

Abstract: A semiconductor device, which ensures device reliability especially in fine regions and enables great capacitance and high-speed operations, has memory cells including, in a first region of a main surface of a semiconductor substrate, a gate insulating film, a floating gate electrode, an interlayer insulating film, a control gate electrode, and source and drain regions of the second conduction type arranged in a matrix, with a shallow isolation structure for isolating the memory cells. When using a shallow structure buried with an insulating film for element isolation, the isolation withstand voltage in fine regions can be prevented from lowering and the variation in threshold level of selective transistors can be reduced. When the memory cells in a memory mat are divided by means of selective transistors, the disturb resistance of the memory cells can be improved.

Abstract: In a flash memory having enhanced reliability, each memory cell has a floating gate electrode which is formed on a semiconductor substrate by being interposed by a gate insulation film, a control gate electrode which is formed on the floating gate electrode by being interposed by an inter-layer film, a pair of n-type semiconductor regions (source regions) formed on the semiconductor substrate to confront two sidewise portions of the floating gate electrode, an n-type semiconductor region (drain region) formed beneath the n-type semiconductor region pair by being interposed by channel well regions, and a common p-well formed beneath the semiconductor region. The n-type semiconductor regions and channel well regions make up the DD structure.

Abstract: In sealing means for a slider unit in which sealing members of foam rubber are arranged to close sidewise clearances left open between a dustproof cover and side walls of a track rail, the improved sealing means is directed to making sure of effective sealing performance, prolonging a durable service life of the sealing member, and also making mounting of the sealing member to the clearances easier. Sealing members of flexible foam rubber rich in restoring force are arranged in the clearance between the dustproof cover and the side walls of the track rail. The sealing members, while fastened to the dustproof cover, are allowed to experience any deformation of expansion/collapse when sideward wings of the slider moves back and forward between the confronting sealing members and the side walls, with keeping close sliding engagement with the associated surfaces of the wings.

Abstract: Each memory cell of a nonvolatile semiconductor memory, essentially, consists of a one-transistor type memory cell such as a MOSFET having a floating gate electrode. When an electric programming operation is carried out, a positive voltage is applied to an n type drain region, a negative voltage is applied to a control gate and a source region is grounded. When an erasing operation is carried out, the positive voltage is applied to the control gate while all the other electrodes and a semiconductor substrate are grounded. Low power consumption can be accomplished because both of the programming operation and erasing operations are carried out by utilizing a tunneling mechanism. Furthermore, because th negative voltage applied to the word line, a drain voltage at the time of programming of data can be lowered, so that degradation of a gate oxide film at a channel portion can be mitigated.

Abstract: Each memory cell of a nonvolatile semiconductor memory, essentially, consists of a one-transistor type memory cell such as a MOSFET having a floating gate electrode. When an electric programming operation is carried out, a positive voltage is applied to an n type drain region, a negative voltage is applied to a control gate and a source region is grounded. When an erasing operation is carried out, the positive voltage is applied to the control gate while all the other electrodes and a semiconductor substrate are grounded. Low power consumption can be accomplished because both of the programming operation and erasing operations are carried out by utilizing a tunneling mechanism. Furthermore, because the negative voltage applied to the word line, a drain voltage at the time of programming of data can be lowered, so that degradation of a gate oxide film at a channel portion can be mitigated.

Abstract: Each memory cell of a nonvolatile semiconductor memory, essentially, consists of a one-transistor type memory cell such as a MOSFET having a floating gate electrode. When an electric programming operation is carried out, a positive voltage is applied to an n type drain region, a negative voltage is applied to a control gate and a source region is grounded. When an erasing operation is carried out, the positive voltage is applied to the control gate while all the other electrodes and a semiconductor substrate are grounded. Low power consumption can be accomplished because both of the programming operation and erasing operations are carried out by utilizing a tunneling mechanism. Furthermore, because the negative voltage applied to the word line, a drain voltage at the time of programming of data can be lowered, so that degradation of a gate oxide film at a channel portion can be mitigated.

Abstract: Each memory cell of a nonvolatile semiconductor memory, essentially, consists of a one-transistor type memory cell such as a MOSFET having a floating gate electrode. When an electric programming operation is carried out, a positive voltage is applied to an n type drain region, a negative voltage is applied to a control gate and a source region is grounded. When an erasing operation is carried out, the positive voltage is applied to the control gate while all the other electrodes and a semiconductor substrate are grounded. Low power consumption can be accomplished because both of the programming operation and erasing operations are carried out by utilizing a tunneling mechanism. Furthermore, because the negative voltage applied to the word line, a drain voltage at the time of programming of data can be lowered, so that degradation of a gate oxide film at a channel portion can be mitigated.

Abstract: Each memory cell of a nonvolatile semiconductor memory, essentially, consists of a one-transistor type memory cell such as a MOSFET having a floating gate electrode. When an electric programming operation is carried out, a positive voltage is applied to an n type drain region, a negative voltage is applied to a control gate and a source region is grounded. When an erasing operation is carried out, the positive voltage is applied to the control gate while all the other electrodes and a semiconductor substrate are grounded. Low power consumption can be accomplished because both of the programming operation and erasing operations are carried out by utilizing a tunneling mechanism. Furthermore, because the negative voltage applied to the word line, a drain voltage at the time of programming of data can be lowered, so that degradation of a gate oxide film at a channel portion can be mitigated.

Abstract: Each memory cell of a nonvolatile semiconductor memory, essentially, consists of a one-transistor type memory cell such as a MOSFET having a floating gate electrode. When an electric programming operation is carried out, a positive voltage is applied to an n type drain region, a negative voltage is applied to a control gate and a source region is grounded. When an erasing operation is carried out, the positive voltage is applied to the control gate while all the other electrodes and a semiconductor substrate are grounded. Low power consumption can be accomplished because both of the programming operation and erasing operations are carried out by utilizing a tunneling mechanism. Furthermore, because the negative voltage applied to the word line, a drain voltage at the time of programming of data can be lowered, so that degradation of a gate oxide film at a channel portion can be mitigated.

Abstract: A transmission line is monitored while the communication is held in a steady state and moving a tone set if there are no tones securing a predetermined value of an S/N ratio. The tone set is not moving if there are at least two tones securing the S/N ratio. The tone set is moved by the predetermined method if there is one tone securing the S/N ratio and it is judged that communication quality can be maintained by moving the tone set in a same tone group. The tone group moved if it is judged that the communication quality cannot be maintained even by executing movement of the tone set in the same tone group.

Abstract: A gate electrode of a field-effect transistor used as a peripheral circuit is constituted by the same gate electrode structure as a double-level gate electrode structure of nonvolatile memory cells, and a contact hole for connecting those conductive films constituting the gate electrode is provided at a location which two-dimensionally overlaps an active area within a plane of the gate electrode.

Abstract: A gate electrode of a field-effect transistor used as a peripheral circuit is constituted by the same gate electrode structure as a double-level gate electrode structure of nonvolatile memory cells, and a contact hole for connecting those conductive films constituting the gate electrode is provided at a location which two-dimensionally overlaps an active area within a plane of the gate electrode.

Abstract: A method of manufacturing a nonvolatile semiconductor memory device which is protected against deterioration in the electron injection/discharge characteristics between a floating gate of a memory cell and a channel. Three layers including a gate oxide film, a first polysilicon layer and a first nitride film are sequentially deposited on a silicon substrate surface and patterned with stripe-like columnwise lines. A second nitride film is formed on side walls of the columnwise lines, respectively. An element isolating insulation film is formed on the silicon substrate surface which is not covered with the first and second nitride films. After removal of the first and second nitride films, a first insulation film is formed on the side walls of the first polysilicon layer.

Abstract: Each memory cell of a nonvolatile semiconductor memory, essentially, consists of a one-transistor type memory cell such as a MOSFET having a floating gate electrode. When an electric programming operation is carried out, a positive voltage is applied to an n type drain region, a negative voltage is applied to a control gate and a source region is grounded. When an erasing operation is carried out, the positive voltage is applied to the control gate while all the other electrodes and a semiconductor substrate are grounded. Low power consumption can be accomplished because both of the programming operation and erasing operations are carried out by utilizing a tunneling mechanism. Furthermore, because the negative voltage applied to the word line, a drain voltage at the time of programming of data can be lowered, so that degradation of a gate oxide film at a channel portion can be mitigated.

Abstract: On a semiconductor substrate of a first conductive type is formed a well layer of the same conductive type as that of the substrate in electrically separated that is, physically separated and electrically isolated, from the substrate, and a MOS transistor, used as a nonvolatile memory cell, forming a drain region and a source region respectively within the well layer is used as a memory cell. Well layers associated with different columns are connected to each other by a well wiring commonly so that operation voltage different from that of the semiconductor substrate is applied thereto. In the case of data erasing, prescribed positive voltage is applied to a well wiring, and prescribed voltage lower than said positive voltage is applied to a selected word line. In the case of data programming, prescribed negative voltage is applied to the well wiring, prescribed voltage higher than said negative voltage is applied to the selected word line.