摘要:
Suppressing a leakage current is required in a flash memory because the channel length is made shorter with a reduction in the memory cell size. In an AND type memory array having an assist electrode, although the memory cell area has been reduced by the field isolation using a MOS transistor, leakage current in the channel direction becomes greater with a reduction in the memory cell size, resulting in problems arising like deterioration of programming characteristics, an increase in the current consumption, and reading failure. To achieve the objective, in the present invention, electrical isolation is performed by controlling at least one assist electrode of the assist electrodes wired in parallel to be a negative voltage during program and read operations and by making the semiconductor substrate surface in the vicinity of the aforementioned assist electrode non-conductive.
摘要:
Suppressing a leakage current is required in a flash memory because the channel length is made shorter with a reduction in the memory cell size. In an AND type memory array having an assist electrode, although the memory cell area has been reduced by the field isolation using a MOS transistor, leakage current in the channel direction becomes greater with a reduction in the memory cell size, resulting in problems arising like deterioration of programming characteristics, an increase in the current consumption, and reading failure. To achieve the objective, in the present invention, electrical isolation is performed by controlling at least one assist electrode of the assist electrodes wired in parallel to be a negative voltage during program and read operations and by making the semiconductor substrate surface in the vicinity of the aforementioned assist electrode non-conductive.
摘要:
Suppressing a leakage current is required in a flash memory because the channel length is made shorter with a reduction in the memory cell size. In an AND type memory array having an assist electrode, although the memory cell area has been reduced by the field isolation using a MOS transistor, leakage current in the channel direction becomes greater with a reduction in the memory cell size, resulting in problems arising like deterioration of programming characteristics, an increase in the current consumption, and reading failure. To achieve the objective, in the present invention, electrical isolation is performed by controlling at least one assist electrode of the assist electrodes wired in parallel to be a negative voltage during program and read operations and by making the semiconductor substrate surface in the vicinity of the aforementioned assist electrode non-conductive.
摘要:
Suppressing a leakage current is required in a flash memory because the channel length is made shorter with a reduction in the memory cell size. In an AND type memory array having an assist electrode, although the memory cell area has been reduced by the field isolation using a MOS transistor, leakage current in the channel direction becomes greater with a reduction in the memory cell size, resulting in problems arising like deterioration of programming characteristics, an increase in the current consumption, and reading failure. To achieve the objective, in the present invention, electrical isolation is performed by controlling at least one assist electrode of the assist electrodes wired in parallel to be a negative voltage during program and read operations and by making the semiconductor substrate surface in the vicinity of the aforementioned assist electrode non-conductive.
摘要:
High integration and making a non-volatile semiconductor memory efficient have been promoted. The memory cell consists of a floating gate, a control gate constituting a word line WL and a MOS transistor having an assist gate. The thickness of the gate oxide film of the assist gate is thinner than the thickness of the gate oxide layer of the floating gate, and the dimensions of the assist gate (gate width) in the direction lying along the word line WL is smaller than the gate length of the floating gate in the direction lying along the word line WL. Moreover, the channel dopant concentration underneath the assist gate is lower than the channel dopant concentration underneath the floating gate.
摘要:
The object of the present invention is to provide a new nonvolatile semiconductor memory device and its manufacturing method for the purpose of miniaturizing a virtual grounding type memory cell based on a three-layer polysilicon gate, enhancing the performance, and boosting the yield. In a memory cell according to the present invention, a floating gate's two end faces perpendicular to a word line and channel are partly placed over the top of a third gate via a dielectric film. The present invention can reduce the memory cell area of a nonvolatile semiconductor memory device, increase the operating speed, and enhances the yield.
摘要:
The object of the present invention is to provide a new nonvolatile semiconductor memory device and its manufacturing method for the purpose of miniaturizing a virtual grounding type memory cell based on a three-layer polysilicon gate, enhancing the performance, and boosting the yield. In a memory cell according to the present invention, a floating gate's two end faces perpendicular to a word line and channel are partly placed over the top of a third gate via a dielectric film. The present invention can reduce the memory cell area of a nonvolatile semiconductor memory device, increase the operating speed, and enhances the yield.
摘要:
A nonvolatile semiconductor memory device improved with integration degree, in which the gate of the selection transistors is separated on each of active regions, first and second selection transistors are arranged in two stages in the direction of the global bit line, the gates for the selection transistors in each stage are disposed on every other active regions, contact holes are formed in mirror asymmetry with respect to line B—B in the connection portion for the active regions, the gate is connected through the contact hole to the wiring, the adjacent active regions are connected entirely in one selection transistor portion and connected in an H-shape for adjacent two active regions in another selection transistor portion, and the contact hole is formed in the connection portion and connected when the global bit line, whereby the pitch for the selection transistor portion can be decreased in the direction of the global bit line.
摘要:
A nonvolatile semiconductor memory device to be manufactured at a high production yield has memory cells disposed in a highly integrated manner by suppressing the occurrence of dislocation typically caused by such highly integrated disposition of the memory cells. In order to achieve is result, each field shielding transistor is formed in a select transistor region having a small isolation width, and 0 V is applied to a gate of the field shielding transistor to isolate each local bit line from the others. The gate of each field shielding transistor is connected to another one with a gate member, so that the layout area is reduced more than when a contact hole is provided directly at the gate of each field shielding transistor.
摘要:
A highly-reliable semiconductor device is realized. For example, each memory cell of a nonvolatile memory included in the semiconductor device is configured to include a source and a drain formed in a P-well, a memory node which is formed on the P-well between the source and the drain via a tunnel insulator and is insulated from its periphery, and a control gate formed on the memory node via an interlayer insulator. When a programming operation using channel hot electrons is to be performed in such a configuration, the P-well is put into an electrically floating state.