Abstract: A memory cell array for a nonvolatile memory device having single-transistor cells (10). Row lines (15) connect the control gates of each row of cells. Column lines (17) connect the drain regions (11) and source regions (12) of columns of cells, such that pairs of row-adjacent cells share a column line (17). Each shared column line (17) has two junctions for each pair of cells that share the column line. One junction is graded for source regions (12) and the other is abrupt for drain regions (11).

Abstract: A lower electrode of a capacitor for use in a semiconductor device includes a first semiconductor layer having a predetermined impurity concentration and a second semiconductor layer having an impurity concentration higher than that of the first semiconductor layer. As a result, intensification of an electric field at an end portion of the capacitor can be reduced. In addition, a word line is formed of a buffer layer and a main conductor layer to reduce a parasitic capacitance between the lower electrode of the capacitor and the word line.

Abstract: A method for writing data to a selected EEPROM memory cell and erasing data in a selected EEPROM memory cell. During writing of the EEPROM memory cell, a tunnel effect is used to draw charges from the charge injection layer of a memory transistor into the drain. A negative voltage lower than ground potential is applied to the control gate of the selected memory cell and the presence or absence of the tunnel effect is controlled by the level of voltage applied to the drain of the selected memory cell. Other memory cells which are not being written with data are maintained free of the tunnel effect by applying a voltage higher than the gate voltage of the selected memory cell, and lower than the threshold voltage of the control gate to the non-selected memory cell with respect to its drain connection. During erasing of a selected memory cell, the power supply voltage for the memory is applied to the control gate of the selected memory cell and the drain and source are grounded.

Abstract: Low leakage trenches for Dynamic Random Access Memory (DRAM) cells and the devices formed thereby are disclosed. In one embodiment of the present invention, [the method includes forming] a diffusion ring is surrounding an upper portion of the trench. In another embodiment, a portion of the diffusion ring extends to the surface of a substrate. The diffusion ring can be formed by outdiffusing a dopant from a doped material deposited within the trench. In a further embodiment, the present [method] invention includes [forming] an insulating ring surrounding an upper portion of the trench. The insulating ring can be formed by thermal oxidation or by etching a sidewall shallow trench and depositing an insulating material therein. In another embodiment, a portion of the insulating ring extends to the surface of the substrate.

Abstract: The address gate electrode of two nonvolatile split gate memory cells are arranged horizontally on the opposite sides of a bit line. The address gate electrode of the first memory cell is nearer to the bit line than the memory gate electrode of the same nonvolatile split gate memory cell. The memory gate electrode of the second nonvolatile split gate memory cell is nearer to the bit line than the address gate electrode of the second nonvolatile split gate memory cell.

Abstract: In a semiconductor memory device according to the present invention, a conductive layer is formed on a field oxide film in a boundary region on the main surface of a semiconductor substrate. A floating gate electrode, an interlayer insulating film, and a control gate electrode are formed on the semiconductor substrate in a memory cell array region with a gate insulating film interposed therebetween. A gate electrode is formed in a peripheral circuit region with the gate insulating film interposed therebetween. An interlayer insulating film is formed on the conductive layer, the gate electrode, and the control gate electrode. A contact hole is formed at a predetermined position of the interlayer insulating film. An interconnection layer is selectively formed on the interlayer insulating film including the inner surface of the contact hole. According to the present invention, it is possible to prevent formation of a concave portion on the surface of the field oxide film in the boundary region.

Abstract: In a semiconductor memory device, when positive high voltages are respectively applied to a control gate(20) and a drain region(14) and a source region(13) is grounded, hot electrons are produced in the boundary between the drain region(14) and a channel region. The hot electrons are injected into a floating gate(18) through a tunnel oxide film(17). Consequently, information is written. At the time of reading out information, the drain region(14) is grounded, a positive read voltage is applied to the source region(13), and a predetermined sense voltage is applied to the control gate(20). At this time, the area between the source and the drain is kept in a non-conduction state if electrons are stored in the floating gate(18), while conduction occurs between the source and the drain if no electrons are stored therein. Since no hot electrons are produced in the boundary between the drain region(14) and the channel region at the time of reading, it is possible to effectively prevent so-called soft writing.

Abstract: A CMOS SRAM cell includes "true" and "false" NMOS word-line access transistors, "true" and "false" NMOS pull-down transistors, and "true" and "false" PMOS pull-down transistors arranged in a classical six-transistor SRAM electrical configuration. "True" and "false" inter-level interconnects of silicidable material provide for respective five-way connections among the transistors. The "true" inter-level interconnect connects: the drain of the "true" pull-up transistor, a gate level polysilicon conductor defining and connecting the gates of the "false" pull-up transistor and the "false" pull-down transistor, and a diffusion region defining and connecting the source of the "true" access transistor and the drain of the "true" pull-down transistor.

Abstract: A non-volatile semiconductor memory cell includes a floating gate dielectrically disposed between a first and a second control gate. The non-volatile memory cell can only be addressed for programming or deprogramming by the simultaneous energization of the first and second control gates. With this unique feature, any memory cell in an memory array can be randomly accessed. Moreover, the two control gates associated with each of the floating gate also increase the coupling capacitances, thereby speeding up operations. The non-volatile memory device of the present invention is ideal to be used for large scale integration applications in which memory cells are arranged in a NAND structure.

Abstract: Superconducting-semiconducting hybrid memories are disclosed. These superconducting-semiconducting hybrid memories utilize semiconductor circuits to store information, and either superconducting or semiconducting or combinations of superconducting and semiconducting circuits, with at least some superconducting circuitry used, to write and read information. The state of memory cells in the hybrid memories is determined by utilizing superconductor current sensing schemes to detect currents in the bit-line, thereby avoiding any bit-line charging delays and other problems associated with purely semiconductor memories. Additional features of the superconducting-semiconducting hybrid memories include wide margins, dense packing of memory cells, low power dissipation and fast access times. Interface curcuitry for converting superconducting signals to signals compatible with semiconductor circuits and for converting semiconductor signals to signals compatible with superconducting circuits is also disclosed.

Abstract: A mask ROM for storing multi-value data has a memory cell comprising a primary conductive region formed by a first conductive type semiconductor, a source region formed in the primary conductive region by a second conductive type semiconductor, a drain region formed in the primary conductive region by the second conductive type semiconductor, a channel region adjacently formed with the source region and the drain region, a gate insulation layer formed on the channel region, and a gate electrode formed on the gate insulation layer, wherein the channel region or the gate electrode is divided into a plurality of parts, each divided part having a different layer thickness from the other or a different transmissivity for ion injection, so as to form a ROM.

Abstract: The invention provides an SRAM memory cell structure permitting increase of integration density while maintaining operation stability. A memory cell in the SRAM includes a pair of access transistors, a pair of driver transistors, and a pair of load transistors. The gate insulating film of access transistor is formed of a single layer of silicon oxide film, while the gate insulating film of driver transistor is formed of a stacked layer formed of a silicon oxide film and a silicon nitride film. The pair of load transistors are formed of two layers of polycrystalline silicon layers stacked upon each other with an insulating film therebetween. A source region and a drain region are formed in each of polycrystalline silicon layers with each channel region therebetween. One drain region forms a gate opposite to the other channel region, while the other drain region forms a gate opposite to the one channel region.

Abstract: A ROM device provides a double density memory array. The word line array is composed of transversely disposed conductors sandwiched between two arrays of bit lines which are orthogonally disposed relative to the word line array. The two arrays of bit lines are stacked with one above and with one below the word line array. A first gate oxide layer is located between the word line array and a first one of the array of bit lines and a second gate oxide layer is located between the word line array and a the other of the arrays of bit lines. The two parallel sets of polysilicon thin, film transistors are formed with the word lines serving as gates for the transistors.

Abstract: Memory cell transistors are provided in which pillar structures or column structures (12, 12a, 14, and 14a) are formed at the face of a semiconductor substrate (10). Floating gates (46) and control gates (52) are formed adjacent to the pillar structures or column structures (12, 12a, 14, and 14a). The floating gates (46) and control gates (52) are insulatively disposed by gate oxide layer (42) and insulating layer (50). Source regions (36, 40, and 48) are implanted in the semiconductor substrate (10). Drain regions (38) are also implanted in the pillar structures or column structures (12, 12a, 14 and 14a).

Abstract: An asymmetrical alternate metal virtual ground (AAMG) EPROM array utilizing an asymmetrical stacked gate cell with an N.sup.- source and four additional select lines is provided. The unintentional write problem associated with the conventional AMG EPROM array is eliminated by utilizing a high select transistor bias voltage and the asymmetrical cell. Soft write of the selected cell is minimized by biasing the source terminal during a read operation. Thus, bit line bias can be significantly increased to enhance the cell current and the memory performance without effecting data retention.

Abstract: An object of the present invention is to provide a semiconductor integrated circuit in which an EEPROM is incorporated in a highly integrated microcomputer having a twin well structure. A twin well region including an n-well region, a p-well region, and a p-type substrate region surrounded by a p-well region are produced in a single semiconductor substrate. A supply voltage system made up of a CPU, a ROM or RAM, a UART, and EEPROM control systems to which the high voltage for the EEPROM is not applied is formed in the twin well region as a CMOS structure, enabling high density integration. A high-voltage system made up of an EEPROM memory cell array and an EEPROM peripheral high-voltage system in the p-type region have an NMOS structure. This arrangement minimizes the substrate effect and enables the high-voltage system to operate normally.

Abstract: A groove is formed in a semiconductor layer, and a source region is formed at a part of the groove within the semiconductor layer. A control gate is buried via a first insulating layer within the groove. A floating gate is formed via a second insulating layer on the control gate. The floating gate extends over the first insulating layer. A drain region is formed within the semiconductor layer apart from the groove.

Abstract: An electrically programmable and erasable floating gate memory device has two substantially identical sections. Each section has a plurality of column address lines, a plurality of row lines and a plurality of source lines. A first plurality of floating gate memory cells has its drain connected to a different one of the column address line, its gate connected to the same first row line and its source connected to the same first source line. A second plurality of floating gate memory cells has its drain connected to a different one of the column address line, its gate connected to the same second row line, different from the first row line, and its source connected to the same first source line. Associated with each section is a plurality of bit latches, one for each column. Reprogramming data is stored in the bit latches. Data from the bit latches of one section are stored in the first plurality of floating gate memory cells.

Abstract: An apparatus for relieving the standby current fail of a memory device which completely relieves a memory device by suppressing the increasing standby current consumption when the standby current is failed by stress during or after fabricating process without any change of standby conditions in a memory device having NAND-type cell array structure, and by using the other data correcting way. By connecting the transistors for the ground string selecting operation in series to the string transistors in order to selectively form the electrical path between the transistor connected to the word line and the ground node, even though the breakdown of the NAND cell occurs, the standby current fail can be prevented by selectively turning on or off the current path in response to the address decoding signal.

Abstract: An improved semiconductor memory device which can increase the capacitor capacitance and improve the processing accuracy of a storage node can be obtained. The device includes a plurality of first field regions which are formed at a predetermined pitch in the running direction of bit line. A plurality of second field regions are formed adjacent to and parallel to the rows formed by the plurality of first field regions, and formed at the same pitch as above. The first field regions and the second field regions are formed shifted from each other by 1/4 pitch in the running direction of bit line. A stacked-type capacitor having bit line buried under cell plate electrode is provided in the first field regions and the second field regions.

Abstract: A main portion of a first word line extends in a direction connecting one diffusion region to the other diffusion region of an access transistor and is located between memory cells, and diverging portions of the first word line alternately extend from both sides of the main portion of the first word line to corresponding adjacent memory cells. A bit line extends in a direction perpendicular to the direction connecting one diffusion region to the other diffusion region, and a second word line extends along the diverging portion of the first word line. When stored data is to be read out from a memory cell, a positive voltage is applied to one first word line corresponding to the memory cell whose data is to be read out, and a zero voltage is applied to the remaining first word lines.

Abstract: A two transistor one capacitor DRAM cell configured with respect to a bit line pair and a single word line in which the gates of the two transistors are connected to the single word line and one of the source/drains of each transistor is connected to a respective electrode of the capacitor and the other of the source/drains of the transistors is connected to a respective bit line of a complementary bit line pair. The storage capacitor is a three dimensional structure with both electrodes being electrically well isolated from electrodes of all other cell storage capacitors. A stacked in trench cell fabrication design is disclosed having a buried strap for connecting the outer electrode to a diffusion region of one transistor and a surface strap for connecting the inner electrode to a diffusion region of the second access transistor.

Abstract: A method for manufacture of a full CMOS type SRAM, comprising the steps of forming a first mask layer on a semiconductor layer, and patterning the first mask layer by photolithography to form semiconductor island layers where a driver MOS transistor and a load MOS transistor are formable with a slight space therebetween; forming a second mask layer on the semiconductor layer, and patterning the second mask layer by photolithography in such a manner as to overlap the region with one of the driver and load MOS transistors, but not to overlap the isolating region between the transistors; masking, with a resist film, the region with the other of the driver and load MOS transistors, and etching the first mask layer while masking the same with the resist film and the second mask layer; and etching the semiconductor layer while masking the same with the first mask layer, thereby forming mutually isolated semiconductor island layers where the driver and load MOS transistors are formed respectively.

Abstract: A nonvolatile memory device for storing data in a flip flop circuit comprising field effect transistors having respective ferroelectric gate films. A pair of writing/reading transistors is connected to the flip flop circuit. Each of the field effect transistors constituting the flip flop circuit retains its channel formation state because of a residual polarization in the ferroelectric gate film. Thus, when power goes OFF, the flip flop circuit retains its state just before power goes OFF. In this way, data can be stored on a nonvolatile basis, and stored data can be read without destroying the data. Additionally, no refreshing is needed, and therefore, a power demand in standby is reduced.

Abstract: A compact static random access memory is formed using both split word lines and self aligned contacts. Self aligned contacts between gates of the pull-down transistor and cross-couple interconnects decreases the critical spacing between elements of the cell and permit the cell to be smaller or more manufacturable. The use of split word lines allows memory cell connections to the bit lines to be located on opposite sides of a memory cell. The connections are widely separated along a direction parallel to the bit lines so perpendicular separation between the bit lines can be decreased. The split word lines also allow the memory cell lay out to be symmetric and thereby increases stability. Use of self aligned contacts further decreases the necessary separation between the bit lines. A further feature is a straight conductor which runs though the center of the memory cell and connects the source of the pull-down transistors to a reference voltage V.sub.SS.

Abstract: A semiconductor device is provided comprising a nonvolatile memory cell through which an LSI and a higher operating speed are achieved. A drain region, an insulating layer partly overlaying the drain region, and a gate electrode formed on the insulating layer are formed on a semiconductor substrate thereby making up a memory cell without a source region. An energy gap between the conduction and valence bands of a semiconductor section including the drain region and the semiconductor substrate is preset to a value corresponding to a first set voltage difference between the drain and the gate. The energy gap between the valence bands (or the conduction bands) of the insulating layer and the semiconductor section at the interface between the semiconductor section and the insulating layer is preset to a value corresponding to a second set voltage difference between the drain and the substrate.

Abstract: A semiconductor memory device which comprises unit memory cells each including two transistors each having a source/drain region and a gate electrode and one capacitor having a capacitor dielectric film, an upper electrode and a lower electrode, the gate electrode of each transistor being connected to a common word line, one source/drain region of each transistor being connected to a bit line and a reversed bit line respectively and the other source/drain region being connected to the upper electrode and the lower electrode respectively, and the bit line, the reversed bit line and the word line being disposed under the lower electrode of the capacitor.

Abstract: A single-transistor non-volatile memory cell MOS transistor with a floating gate and a control gate using two levels of polysilicon and a tunnel dielectric that overlaps the drain area wherein a tunneling of charge can take place between the drain and the floating gate by means of a system of applied voltages to the control gate and drain.

Abstract: A floating gate tunneling metal oxide semiconductor transistor is formed on a semiconductive substrate as a cell of electrically erasable programmable read-only memory. The transistor includes a source and a drain spaced apart to define a channel region therebetween in the substrate. An insulated floating gate at least partially overlies the channel region and is capacitively coupled with the substrate. A control gate is insulatively disposed above the conductive layer and spans the channel region. The withstanding voltage of the drain is specifically set to range from a first voltage adapted to be applied to the drain during a read operation to a second voltage applied thereto for forcing the conductive layer to discharge.

Abstract: Two addresses of an integrated circuit are selected to define a portion of the die which is functional and the portion of the die which will not be used. An input structure for addresses, which may be added to part of the electrostatic discharge (ESD) input structure of a pin, allows an address signal to be set to a predetermined logic level and to not be bonded out to the package. Additionally, another input structure allows the mapping of a signal pin to be changed. The function of a pin may need to be changed to accommodate a pinout for a different density device. This is useful when a die is put into a smaller density device package which has a pin out that does not accommodate the die. In this way, partially functional die that previously were discarded may be utilized, thereby recouping potential losses during manufacturing.

Abstract: An integrated circuit, illustratively an SRAM, with pull down gates symmetrically positioned with respect to the ground line is disclosed. The symmetric positioning helps to insure cell stability.

Abstract: A latch (80) utilizing stacked MOS technology is provided. Latch (80) is formed generally in relation to a semiconductor substrate (82). An N channel transistor is provided with first and second diffused regions (96 98) and a gate conductor (86) . A P channel transistor is provided with first and second doped regions (106, 110) having a channel region (108) therebetween. The second diffused region (98) of the N channel transistor also functions as the gate conductor for the P channel transistor. A capacitive element exists by having an insulating layer (84) or layers (84, 100) between first doped region (104) and second diffused region (98).

Abstract: A non-volatile memory comprises memory cells M arranged in a matrix (MB), word lines (W1 to Wn) for row selection, sub-bit lines (B: B12, B21, B22, B31), sub-column lines (C: C11, C12, C22), a column selection circuit 1, a bit line selection circuit 2, and a column line selection circuit 3. The word lines (W1 to Wn) are used as gates common to the rows of the memory cells M, a group of sub-bit lines B and sub-column lines C is selected by the column selection circuit 1, an even-numbered or odd-numbered sub-bit line B is selected from each group and connected to any one of main bit lines (B1, B2 and B3) by the bit line selection circuit 2, and an even-numbered or odd-numbered sub-column line (C) is selected from each group and connected to any one of main column lines (C1 and C2) by the column line selection circuit 3.

Abstract: Each unit cell (10) of a flash EEPROM array (50) includes a control gate (38) having a section (38b) disposed in series between a program section (34a) of a floating gate (34) and a source (18) to provide threshold voltage control for erasure. The floating gate (34) further has an erase section (34b) which extends from the program section (34a) around an end of a channel (22) to the source (18). A thin tunnel oxide layer (32) is formed between an end portion (34c) of the erase section (34b) and an underlying portion of the source (18) which enables the floating gate (34) to be erased by Fowler-Nordheim tunneling from the end portion (34c) through the oxide layer (32) to the source (18) with low applied voltages.

Abstract: A plurality of trap-type memory transistors are formed in separate wells of a semiconductor substrate, and arranged to constitute a memory matrix. Each well contains the memory transistors belonging to one column of the memory matrix. Each of gate control lines is connected to gate electrodes of the memory transistors belonging to the same row of the memory matrix. One of the memory transistors is selected for writing by separately applying control voltages to the respective wells from an X-decoder, and separately applying control voltages to the respective gate control lines from an Y-decoder. The well and gate control line associated with the memory transistor to be selected are supplied with different voltages than those for the remaining wells and gate control lines.

Abstract: A semiconductor flash memory cell which includes a P type substrate with an N type well formed therein followed by a P type well formed within the N well. An N type drain is formed in the P well as is an N type source, with the drain and source being spaced apart so as to create a channel region therebetween. A floating gate is disposed over only a part of the channel and a first segment of a control gate is disposed over the remainder of the channel. A second segment of the control gate is disposed over the floating gate. The arrangement of the floating and control gate functions to eliminate adverse effects of over erase. In addition, the well-within-a-well structure enables biasing voltages to be applied during erase which forces electrons removed from the floating gate to enter the channel region, rather than the drain region thereby increasing the program/erase cycle endurance of the cell.

Abstract: An electronic module (10) includes a processor (12), having a set of contacts (26) coupled to a set of metallized areas (24) on a first device carrier (16), and a programmable memory device (14), having a set of contacts (40) coupled to each of a set of conductive members (46) depending from a second device carrier (33) stacked above the first carrier. Interposed between the two device carriers is an interposer layer (48), a routing layer (60) and a conduction layer (70) which collectively provide a path between a separate first metallized area (24) on the first device carrier and a conductive member (46) on the second device carrier to couple the processor to the memory. At least one clip (72) releasably secures the second device carrier to the first device carrier to allow the second device carrier to be separated so that the programmable memory device can be programmed off-line.

Abstract: A single poly EE cell and an array using said cell, with the array being provided electrical connections such that the select gate for the read select transistor and the select gate for the write select transistor may be separately controlled. In the array, first level metal is utilized for connection to the gates of the read and write select transistors and second level metal is utilized for connection to the product term connections of the cell.

Abstract: The present invention provides nonvolatile semiconductor memory which has advantages permitting the cell of the memory circuit to integrate, the memory circuit to be easy to manufacture, and the manufacturing expense to be cut down. The nonvolatile memory (21) comprises a P type well for which a N+ type source (4) and a N+ type drain (3) is provided. A surface of a space between the source (4) and the drain (3) comprises a first portion (10a) and a second portion (10b). An insulating layer (6) for holding electrons spans the surface of the space. A memory gate electrode (5) is on the insulating layer (6) and spans the first portion (10a). The surface of the second portion (10b) and a part of the surface of the memory gate electrode (5) is covered with a first region electrode (24) attaching to the source (4). But the first region electrode (24) is insulated from the memory gate electrode (5) with the insulating layer (8).

Abstract: In a semiconductor memory device, a first sidewall and a second sidewall are formed simultaneously for a memory cell section and a peripheral circuit section, and a high impurity concentration region is formed by being delimited by the second sidewall in the memory cell section, while a high impurity concentration section is formed by being delimited by the first sidewall in the peripheral circuit section. In this manner, MOS transistors having different LDD widths of the low impurity concentration regions and hence different characteristics, in which the MOS transistor of the memory cell section has improved voltage withstand properties and the MOS transistor of the peripheral circuit section has improved current driving capabilities, may be formed on the same substrate.

Abstract: A MOS semiconductor memory device comprises a semiconductor substrate of a first conductive type; impurity diffused regions of a second conductive type different from the first conductive type formed into a plurality of spaced columns extending in a first direction on one surface of the semiconductor substrate and having functions of bit lines; a plurality of columns of element isolation insulating films formed on the impurity diffused regions of the second conductive type, with active regions formed therebetween; a plurality of MOS transistors formed in the active regions aligned in each of a plurality of rows extending in a second direction substantially perpendicular to the first direction, each MOS transistor including a gate formed on a part of the active region with a gate insulating film therebetween and source and drain formed in the impurity diffused regions of the second conductive type; and word lines each connected electrically to the gates of the MOS transistors aligned in each of the rows and ex

Abstract: A dynamic RAM is provided with enhanced charge storage capacity by increasing the surface area between the two electrodes of the storage capacitor. The first electrode consists of a thick conductive layer whose vertical sidewalls provide the extra surface area for charge storage. The second electrode is used to partially planarize the surface topology. The first electrode can also be used as the gate of a sensing transistor in a signal amplifying cell, as well as in multiport and multistate dynamic RAM cells.

Abstract: A non-volatile memory device includes a semiconductor layer, floating gates, control gates, pairs of first and second impurity diffused layers formed in the semiconductor layer and located on both sides of the control gates Word lines are electrically connected to the control gates, and bit lines are electrically connected to the first impurity diffused layers and perpendicular to the word lines Wiring electrodes are electrically connected to the second impurity diffused layers, and run in a direction in which the bit lines run. Areas including the pairs of first and second impurity diffused areas are obliquely arranged with respect to the bit lines.

Abstract: A carrier injected dynamic random access memory is defined. A depletion region adjacent to a source/drain region of a transistor is used as a storage cell in a memory array, and logic levels may then be measured by sensing the conductive portion. A low logic level is stored by a reduced formation of the depletion adjacent the conductive portion. These logic levels are sensed and periodically refreshed by conduction through the access device. The logic levels may be read by measuring potential through the access device, or by measuring punch through voltage between the source/drain region and a nearby conductive region. As the level of injected carriers increases, the punch through also increases. A punch through results in a readable increase in current through the access device, thereby providing an indicia of a in logic level.

Abstract: A method for manufacturing highly integrated NAND and NOR logic mask read only memory (MROM) devices is disclosed. Over the top surface of a semiconductor substrate, where a first polysilicon layer is formed, a pattern of a gate electrode is formed along a word line in the order of odd numbers or even numbers. Next, an insulation layer having a thickness of a submicron range is formed over the top surface of the substrate. And then a photoresist is covered and an etch back process is performed. Thereafter, the exposed insulation layer caused by the etch back process and the polysilicon layer are selectively etched to form a word line spacing corresponding to a thickness of the insulation layer. Thus, spacing between adjacent word lines can be minimized and a process margin can be sufficiently ensured.

Abstract: A semiconductor memory device includes a single crystalline semiconductor substrate having a main surface, a plurality of active regions formed at the main surface, and an isolation region which is formed at the main surface and isolates the active regions from one another. Each of the active regions has a transistor region and a capacitor region. The capacitor region has a trench formed in the single crystalline semiconductor substrate. An inner wall of the trench is covered with an insulating layer. At least a portion of the transistor region and the insulating layer are both covered with a semiconductor layer. A portion of the semiconductor layer which covers at least the portion of the transistor region is an epitaxial layer. A portion of the semiconductor layer which covers the insulating layer is a polycrystalline layer, which functions as a storage node of a capacitor.

Abstract: A MOS transistor has a floating gate, which forms a memory cell of EPROM, and a control gate. The control gate is formed of a thin film. An impurity concentration of a region corresponding to the floating gate is lower than that of the other regions. The region having low impurity concentration functions as a channel region of a thin film transistor. The floating gate functions as a gate of the thin film transistor. In the memory cell in which an electron is written in the floating gate, a threshold voltage of the thin film transistor rises, and the thin film transistor is set to be in an off state. In the memory cell in which no electron is written in the floating gate, the threshold voltage of the thin film transistor lowers, and the thin film transistor is set to be in an on state.

Abstract: The present invention provides a self-aligned trench isolation scheme for the MOS select transistors in an alternate metal virtual ground (AMG) EPROM array architecture. The new isolation scheme allows bit line to bit line spacing to be scaled to 0.6 .mu.m and below without compromising either data retention or memory performance characteristics. A new poly stack self-aligned etch scheme is also provided to scale the word line spacing to 0.6 .mu.m and below and, thus, allow a 64 Mbit EPROM array to be realized.

Abstract: Novel memory cells utilize source-side injection, allowing very small programming currents. If desired, to-be-programmed cells are programmed simultaneously while not requiring an unacceptably large programming current for any given programming operation. In one embodiment, memory arrays are organized in sectors with each sector being formed of a single column or a group of columns having their control gates connected in common. In one embodiment, a high speed shift register is used in place of a row decoder to serially shift in data for the word lines, with all data for each word line of a sector being contained in the shift register on completion of its serial loading. In one embodiment, speed is improved by utilizing a parallel loaded buffer register which receives parallel data from the high speed shift register and holds that data during the write operation, allowing the shift register to receive serial loaded data during the write operation for use in a subsequent write operation.

Abstract: A semiconductor memory device has a diffusive region for a source formed in the shape of a band on a substrate; a diffusive region for a drain formed in the shape of a band in parallel with the diffusive region for a source and alternated with this diffusive region for a source; a first word line layer formed such that the first word line layer crosses the diffusive regions for a source and a drain; and a second word line layer formed in parallel with the first word line layer. The semiconductor memory device further has a channel region including an a-region on a substrate surface located on the lower side of a flat portion within a region prescribed between the diffusive regions for a source and a drain; and two b-regions on the substrate surface arranged on both sides of the a-region and located on the lower sides of first and second side wall portions.