Abstract: A semiconductor memory cell having a data storage element constructed around an ultra-thin dielectric, such as a gate oxide, is used to store information by stressing the ultra-thin dielectric into breakdown (soft or hard breakdown) to set the leakage current level of the memory cell. The memory cell is read by sensing the current drawn by the cell. A suitable ultra-thin dielectric is high quality gate oxide of about 50 Å thickness or less, as commonly available from presently available advanced CMOS logic processes.

Abstract: A field programmable gate array (FPGA) cell useful in a FPGA array having column bitlines, read bitlines, and row wordlines is disclosed. The cell comprises a capacitor having a first terminal and a second terminal, the first terminal connected to a column bitline, said second terminal connected to a switch control node, the capacitor having a dielectric between the first and second terminal. The cell also includes a select transistor having a gate, a source, and a drain, the gate connected to the read bitline, the source connected to the switch control node, and the drain connected to a row wordline. Finally, the cell includes a switch being controlled by the switch control node.

Abstract: A programmable memory cell comprised of a transistor located at the crosspoint of a column bitline and a row wordline is disclosed. The transistor has its gate formed from the column bitline and its source connected to the row wordline. The memory cell is programmed by applying a voltage potential between the column bitline and the row wordline to produce a programmed n+ region in the substrate underlying the gate of the transistor.

Abstract: A programmable memory cell comprised of a transistor located at the crosspoint of a column bitline and a row wordline is disclosed. The transistor has its gate formed from the column bitline and its source connected to the row wordline. The memory cell is programmed by applying a voltage potential between the column bitline and the row wordline to produce a programmed n+ region in the substrate underlying the gate of the transistor.

Abstract: A semiconductor memory cell having a data storage element constructed around an ultra-thin dielectric, such as a gate oxide, is used to store information by stressing the ultra-thin dielectric into breakdown (soft or hard breakdown) to set the leakage current level of the memory cell. The memory cell is read by sensing the current drawn by the cell. A suitable ultra-thin dielectric is high quality gate oxide of about 50 Å thickness or less, as commonly available from presently available advanced CMOS logic processes.

Abstract: A reprogrammable non-volatile memory array and constituent memory cells is disclosed. The semiconductor memory cells each have a data storage element constructed around an ultra-thin dielectric, such as a gate oxide. The gate oxide is used to store information by stressing the ultra-thin dielectric into breakdown (soft or hard breakdown) to set the leakage current level of the memory cell. The memory cell is read by sensing the current drawn by the cell. A suitable ultra-thin dielectric is high quality gate oxide of about 50 Å thickness or less, as commonly available from presently available advanced CMOS logic processes. The memory cells are first programmed by stressing the gate oxide until soft breakdown occurs. The memory cells are then subsequently reprogrammed by increasing the breakdown of the gate oxide.

Abstract: A reprogrammable non-volatile memory array and constituent memory cells is disclosed. The semiconductor memory cells each have a data storage element constructed around an ultra-thin dielectric, such as a gate oxide. The gate oxide is used to store information by stressing the ultra-thin dielectric into breakdown (soft or hard breakdown) to set the leakage current level of the memory cell. The memory cell is read by sensing the current drawn by the cell. A suitable ultra-thin dielectric is high quality gate oxide of about 50 Å thickness or less, as commonly available from presently available advanced CMOS logic processes. The memory cells are first programmed by stressing the gate oxide until soft breakdown occurs. The memory cells are then subsequently reprogrammed by increasing the breakdown of the gate oxide.

Abstract: A programming circuit includes a wordline decoder, an adjustable voltage generator, and a column transistor. The programming circuit is useful in programming a memory cell comprised of a select transistor and a data storage element. The data storage element is programmed by a programming current. The amount of the programming current can be modulated by the column transistor, the select transistor, or the adjustable voltage generator.

Abstract: A programmable interconnect cell for selectively connecting circuit nodes of a field programmable integrated circuit array in a semiconductor substrate includes a switch field effect transistor, a sense field effect transistor, and an electron tunneling device with the transistors and electron tunneling device having interconnected floating gates and interconnected control gates. The floating gates comprise a first polysilicon layer which is restricted to each cell, and the control gates comprise a second polysilicon layer which extends to adjacent cells in the row. The source/drain regions of the sense transistor extend to source/drain regions of sense amplifiers in adjacent rows. Programming and erasing of the switch transistor is effected entirely by electron tunneling in the electron tunneling device.

Abstract: Disclosed is a FPGA cell and array structure which use FN tunneling for program and erase. Each cell comprises a switch floating gate field effect transistor and a sense floating gate field effect transistor with the floating gates being common and the control gates being common. Programming of a cell is effected by voltage biasing the common control gate line and the source/drains of the sense transistor. The source/drains of the sense field effect transistor are formed from buried doped layers (e.g. N+ in a P-doped substrate) which are formed prior to formation of the polysilicon floating gate and control gate. Lateral diffusion of dopant from the buried source/drains into the channel beneath the floating gate facilitates electron tunneling during erase and program operations, and the graded junctions of the buried source/drains lower band-to-band tunneling leakage.

Abstract: Disclosed is a FPGA cell and array structure which use FN tunneling for program and erase. Each cell comprises a switch floating gate field effect transistor and a sense floating gate field effect transistor with the floating gates being common and the control gates being common. Programming of a cell is effected through a buried bitline in juxtaposition with the switch transistor and the sense transistor over which are the floating gate and the control gate. The sense transistor can be fabricated simultaneously with fabrication of the switch transistor whereby the two transistors are identical in dopant concentrations.

Abstract: The present invention provides for an improved EPROM transistor cell which forms the programming portion of the programmable interconnect interconnect of an FPGA integrated circuit, and a method of manufacturing the EPROM cell. The EPROM cell has a floating gate disposed over a P region of the substrate. Aligned with one edge of the floating gate and at the surface of the substrate is a lightly doped P- region; on the opposite edge of the floating gate is a heavily doped N+ region. A control gate lies over the P-, P substrate and over the N+ region. N+ regions are formed at the opposite edges of the control gate. One N+ region is contiguous to the P- region and forms the source of the EPROM cell and the other N+ region is connected to the N+ region under the control gate and forms the drain of the EPROM cell. This structure allows for easy process control of the V.sub.

Abstract: A channel region formation process in field effect transistors directed toward reducing threshold voltage sensitivity to variations in gate length resulting from manufacturing techniques. A polysilicon gate is formed over the substrate and a channel region is subsequently implanted at a large angle measured from perpendicular to the substrate. Large angle implantation results in a non-uniform doping concentration in the channel region, improving threshold voltage sensitivity. Improvement can also be seen in other parameters, including source-drain current, substrate current, leakage current, magnification factor, and hot electron channel injection efficiency.

Abstract: Disclosed is a FPGA cell and array structure which use FN tunneling for program and erase. Each cell comprises a switch floating gate field effect transistor and a sense floating gate field effect transistor with the floating gates being common and the control gates being common. Programming of a cell is effected by voltage biasing the common control gate line and the source/drains of the sense transistor.

Abstract: The present invention provides for a programming portion of an FPGA cell of an integrated circuit and a process of manufacturing the programming portion. The programming portion has an EPROM transistor and a separated select transistor with the gate of the select transistor connected to the control gate of the EPROM transistor. Both transistors share a common N+ source/drain region, which is self-aligned with the gates of both transistors. With the select transistor separated from the EPROM transistor and the self-aligned common N+ region, the threshold voltage V.sub.T of the select transistor can be set precisely. This allows good control over the programming voltage for the control gate of the EPROM transistor and the time to program the floating gate of the EPROM transistor.

Abstract: The present invention provides for a novel programming operation of a programming portion of an FPGA interconnect cell. The programming portion has an EPROM transistor and a separated select transistor with the gate of the select transistor connected to the control gate of the EPROM transistor. Both transistors have N+ source/drain regions and share a common N+ source/drain region. A first interconnection line is connected to the N+ source/drain region of the EPROM transistor and a second interconnection line connected to the N+ source/drain region of the select transistor. By setting the first interconnection line and the second interconnection line at respective voltages so that majority charge carriers flow from the N+ region of the EPROM transistor through the common N+ region to the N+ source/drain region of the select transistor during a programming operation of a selected FPGA interconnect cell in an array of such cells, drain disturb effects on the unselected cells are avoided.

Abstract: A low power CMOS array cell for use in a PLD device is disclosed. The cell utilizes controlled avalanche injection at the p-n junction of a transistor in the CMOS cell for programming and erasing, resulting in lower voltages than with Fowler-Nordheim tunneling and lower currents than channel hot carrier injection during program and erase. A depletion transistor having a gate connected to its source has a source-drain path supplying current to the CMOS cell to limit current required during avalanche injection.

Abstract: A memory cell for a programmable logic device (PLD) and method for programming the memory cell. The memory cell includes components typically found in a memory cell for a PLD including an NMOS transistor having a floating gate, and two capacitors coupled to the floating gate, one capacitor being a tunneling capacitor enabling charge to be added to and removed from the floating gate. The memory cell further includes an NMOS pass gate transistor for supplying charge to the tunneling capacitor, but unlike conventional NMOS pass gates, it has a reduced threshold so that during programming when a programming voltage is applied to its drain, it can be turned on with an identical programming voltage applied to its gate, rather than requiring that its gate voltage be pumped above its drain voltage during programming. The reduced threshold can be obtained by removing the vt implant and punch through implant normally provided in its channel, or by other means.