摘要:
A semiconductor substrate of a first conductivity type has formed on its main surface a floating gate through a first gate insulating film and has further formed over the floating gate a control gate through a second gate insulating film. In one of a paired source and drain and across which there is provided the floating gate insulately above the main surface of the substrate, a semiconductor region of second conductivity type having a lower impurity concentration than that of the paired source and drain is formed in a portion of the substrate overlapping the floating gate. A nonvolatile memory device thus constructed has its writing operation carried out by extracting electrons from the floating gate to the other of the paired source and drain having a semiconductor region of the second conductivity type, having a higher impurity concentration, by an F-N tunneling of electrons flowing through the first gate insulating film and its erasing operation carried out by injecting from the paired source and drain or the semiconductor substrate into the floating gate by the F-N tunneling of electrons flowing through the first gate insulating film. Data lines or source lines can be shared between memory cells adjacent to each other in a word line direction so that the memory cells can be substantially small-sized. The writing operation and the erasing operation can be carried out by the tunnel current so that the corresponding necessary high voltages can be generated by the internal circuits.
摘要:
There are provided a plurality of ferroelectric capacitors each of which having one of a pair of electrodes thereof connected with one terminal of a switch element which has the control terminal thereof connected with a first address selecting line. Second address selecting lines are respectively connected with the other electrodes of the ferroelectric capacitors to construct a unit memory circuit. When the switch element is turned ON by the first address selecting line, one of the second address selecting line is brought into a selecting state to feed such a voltage as to polarize the ferroelectric capacitors. The remaining address selecting lines are set to an unselect potential so that the voltage to be applied to the unselected ferroelectric capacitors coupled to the remaining address selecting lines may be about one half as high as that applied to the selected ferroelectric capacitor. When the switch element is turned ON by the first address selecting line, the second address selecting lines are fed with such an unselect potential as to reduce the voltage to be applied to the ferroelectric capacitors substantially to zero. The stress to the ferroelectric capacitors of the unit memory circuit corresponding to the unselected switch element can be reduced because no voltage is applied to the ferroelectric capacitors.
摘要:
There are provided a plurality of ferroelectric capacitors each of which having one of a pair of electrodes thereof connected with one terminal of a switch element which has the control terminal thereof connected with a first address selecting line. Second address selecting lines are respectively connected with the other electrodes of the ferroelectric capacitors to construct a unit memory circuit. When the switch element is turned ON by the first address selecting line, one of the second address selecting lines is brought into a selecting state to feed such a voltage as to polarize the ferroelectric capacitors. The remaining address selecting lines are set to an unselect potential so that the voltage to be applied to the unselected ferroelectric capacitors coupled to the remaining address selecting lines may be about one half as high as that applied to the selected ferroelectric capacitor. When the switch element is turned ON by the first address selecting line, the second address selecting lines are fed with such an unselect potential as to reduce the voltage to be applied to the ferroelectric capacitors substantially to zero. The stress to the ferroelectric capacitors of the unit memory circuit corresponding to the unselected switch element can be reduced because no voltage is applied to the ferroelectric capacitors.
摘要:
A microcomputer mounted on a single semiconductor chip includes a central processing unit and a nonvolatile flash memory which allows the information to be processed by the central processing unit to be re-programmed by electrical erasing and programming operations. The microcomputer is provided with a normal power supply voltage terminal and a programming power supply voltage terminal and also incorporates a power supply voltage level detection device and an internal voltage boost circuit to decide the re-programming mode for the flash memory according to the level of the voltage supplied and to select between the boost voltage and the external high voltage in performing the erasing and programming of data.
摘要:
Disclosed is a semiconductor integrated circuit device which includes first field effect transistors with an LDD structure having a floating gate in memory cells and second field effect transistors with an LDD structure as elements other than memory cells, and which is used as an EPROM. A shallow, low impurity concentration region of the first field effect transistor as a part of its source or drain region has a higher impurity concentration than a shallow, low impurity concentration region of the second field effect transistor as a part of its source or drain region.
摘要:
A method of fabricating a second semiconductor integrated circuit device includes steps of forming a first semiconductor integrated circuit device which has a microcomputer and is furnished with an EPROM; determining a program for controlling the microcomputer and to be set in the EPROM (performing an initial evaluation) while information is being written into and erased from the EPROM built in the first semiconductor integrated circuit device; and thereafter forming a second semiconductor integrated circuit device in which the EPROM of the first semiconductor integrated circuit device is replaced with a mask ROM. In replacing the EPROM with the mask ROM, the peripheral circuits required for both the EPROM and the mask ROM have their circuit arrangements held basically the same, and specific peripheral circuits for use in only the EPROM have their circuit regions left as they are as logically inactive regions.
摘要:
Disclosed is a semiconductor integrated circuit device which includes first field effect transistors of a LDD structure having a floating gate as memory cells and second field effect transistors of the LDD structure as elements other than the memory cells, and which is used as EPROM. A shallow, low impurity concentration region of the first field effect transistor as a part of its source or drain region has a higher impurity concentration than a shallow, low impurity concentration region of the second field effect transistor as a part of its source or drain region.
摘要:
Disclosed herein is a MOS-type field-effect transistor in which a semiconductor region having the same type of conductivity as the substrate and an impurity concentration higher than that of the substrate is formed under the channel so as to come at both ends thereof into contact with the source and drain regions. The semiconductor region restricts the extension of depletion layer from the source and drain regions, and restricts the short-channel effect. The junction capacity is small between the semiconductor region and the source and drain regions.
摘要:
The semiconductive roller according to the present invention includes a roller body having an outer peripheral surface made of a crosslinked substance of a semiconductive rubber composition and exhibiting Shore A hardness of not more than 60, the semiconductive rubber composition contains a base polymer made of a mixture of (1) mixed rubber N of liquid nitrile rubber and solid nitrile rubber, (2) chloroprene rubber C, and (3) epichlorohydrin rubber E in a mass ratio (C+E)/N of 10/90 to 80/20, the ratios of the chloroprene rubber and the epichlorohydrin rubber in the total quantity of the base polymer are not less than 5 mass % and not less than 5 mass % respectively, and roller resistance at an applied voltage of 5 V is not less than 104Ω and not more than 109Ω.
摘要:
A nonvolatile storage element of a single-layer gate type structure is arranged so that a floating gate is formed of a conductive layer which partly overlaps with a control gate, formed of a diffused layer, and is provided with a barrier layer covering a part of or the whole surface of the floating gate. Nonvolatile storage elements characterized as such are used for redundancy control of defects or change of functions.