Abstract:
An electrically rewritable non-volatile memory device is configured by the EEPROM 3, and an electrically non-rewritable non-volatile memory device is configured by the OTPROM 4a. Both the EEPROM 3 and the OTPROM 4a are configured by phase change memory devices each of which can be fabricated in the same fabrication step and at a low cost. The EEPROM3 uses a phase change memory device in which an amorphous state and a crystal state of a phase change material are used for memory information, while the OTPROM 4a uses a phase change memory device in which a non-disconnection state and a disconnection state of a phase change material are used for memory information.
Abstract:
A semiconductor device includes a plurality of nonvolatile memory cells (1). Each of the nonvolatile memory cells comprises a MOS type first transistor section (3) used for information storage, and a MOS type second transistor section (4) which selects the first transistor section. The second transistor section has a bit line electrode (16) connected to a bit line, and a control gate electrode (18) connected to a control gate control line. The first transistor section has a source line electrode (10) connected to a source line, a memory gate electrode (14) connected to a memory gate control line, and a charge storage region (11) disposed directly below the memory gate electrode. A gate withstand voltage of the second transistor section is lower than that of the first transistor section. Assuming that the thickness of a gate insulating film of the second transistor section is defined as tc and the thickness of a gate insulating film of the first transistor section is defined as tm, they have a relationship of tc
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 transistor 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:
A semiconductor device includes a plurality of nonvolatile memory cells (1). Each of the nonvolatile memory cells comprises a MOS type first transistor section (3) used for information storage, and a MOS type second transistor section (4) which selects the first transistor section. The second transistor section has a bit line electrode (16) connected to a bit line, and a control gate electrode (18) connected to a control gate control line. The first transistor section has a source line electrode (10) connected to a source line, a memory gate electrode (14) connected to a memory gate control line, and a charge storage region (11) disposed directly below the memory gate electrode. A gate withstand voltage of the second transistor section is lower than that of the first transistor section. Assuming that the thickness of a gate insulating film of the second transistor section is defined as tc and the thickness of a gate insulating film of the first transistor section is defined as tm, they have a relationship of tc
Abstract:
Characteristics of a nonvolatile semiconductor memory device are improved. The memory cell comprises: an ONO film constituted by a silicon nitride film SIN for accumulating charge and by oxide films BOTOX and TOPOX disposed thereon and thereunder; a memory gate electrode MG disposed at an upper portion thereof; a select gate electrode SG disposed at a side portion thereof through the ONO film; a gate oxide film SGOX disposed thereunder. By applying a potential to a select gate electrode SG of a memory cell having a source region MS and a drain region MD and to the source region MS and by accelerating electrons flowing in a channel through a high electric field produced between a channel end of the select transistor and an end of an n-type doped region ME disposed under the memory gate electrode MG, hot holes are generated by impact ionization, and the hot holes are injected into a silicon nitride film SIN by a negative potential applied to the memory gate electrode MG, and thereby an erase operation is performed.
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:
A method for settling threshold voltages of word lines on a predetermined level in an erasing processing of a non-volatile semiconductor memory device so as to speed up the erasing processing. A word latch circuit is provided for each word line and the threshold voltage of each memory cell is managed for each word line in a selected memory block. Each word latch circuit is shared by a plurality of word lines so as to reduce the required chip area. A rewriting voltage is set for each finished non-volatile memory and the voltage information is stored in the boot area of the non-volatile memory, so that the voltage is recognized by the system each time the system is powered.
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.