Abstract: A CMOS electrostatic discharge (ESD) protection circuit in a substrate of a first conductivity type, in which a discharge circuit having an MOS transistor in the substrate is operable to discharge the ESD pulse to ground. A drive circuit has a plurality of forward-biased diodes in separate wells of the opposite conductivity type, connected as a string in forward direction. During an ESD event, the diode string uses a portion of the ESD pulse's voltage to enter a high-conductance, conductivity-modulated state, and to provide a large substrate current, and consequently a substrate voltage drop, to turn-on the MOS transistor so that it will ground the ESD pulse.

Abstract: Depletion-mode ferroelectric transistors are adapted for use as non-volatile memory cells. Various embodiments are described having a diode interposed between the bit line and a source/drain region of the transistor for added margin against read disturb. Various additional embodiments are described having an array architecture such that two memory cells sharing the same bit line also share the same program line. Using this configuration, non-selected cells are readily supplied with gate/source voltages sufficient to maintain the cells in a deactivated state during read and write operations on selected cells.

Abstract: An integrated circuit located between isolation trenches at the surface of a semiconductor chip comprising a first well of a first conductivity type having a first resistivity. This first well has a shallow buried region of higher resistivity than the first resistivity, extending between the isolation trenches and created by a compensating doping process. The circuit further comprises a second well of the opposite conductivity type extending to the surface between the isolation trenches, having a contact region and forming a junction with the shallow buried region of the first well, substantially parallel to the surface. Finally, the circuit has a MOS transistor located in the second well, spaced from the contact region, and having source, gate and drain regions at the surface. This space is predetermined to create a small voltage drop in I/O transistors for conditioning signals and power to a pad, or large voltage drops in ESD circuits for protecting the active circuitry connected to a pad.

Abstract: Structure and fabrication method of a lateral MOS transistor, positioned on the surface of an integrated circuit fabricated in a semiconductor of a first conductivity type, comprising a source and a drain, each having at the surface a region of the opposite conductivity type extending to the centrally located gate, defining the active area of said transistor; and a semiconductor region within said semiconductor of the first conductivity type, having a resistivity higher than the remainder of the semiconductor, this region extending vertically below the transistor while laterally limited to the area of the transistor such that the resistivity under the gate is different from the resistivity under the source and drain regions.

Abstract: Protection circuitry (100) for protecting an integrated circuit against an ESD pulse is provided. The protection circuitry (100) includes a discharge circuitry (101) on a substrate (106) that discharges an ESD pulse to the integrated circuit to ground (104a). The protection circuitry (100) also includes a drive circuitry (102) that uses a portion of the ESD pulse voltage to bias the substrate (106) using a first guard ring (110) in the substrate (106), which surrounds the discharge circuitry (101) and drive circuitry (102). The protection circuitry (100) further includes a second guard ring (120) in substrate (106), which surrounds the first guard ring (110) and connects to Vss/ground potential (104c), thereby providing uniformity of the substrate bias.

Abstract: On the surface of a semiconductor material of a first conductivity type 101a, a lateral MOS transistor 100 is described surrounded by a well 171 of the opposite conductivity type and, nested within the well, an electrical isolation region 102. The semiconductor region 101a embedding this transistor has a resistivity higher than the remainder of the semiconductor material 101 and further contains a buried layer 160 of the opposite conductivity type. This layer 160 extends laterally to the wells 171, thereby electrically isolating the near-surface portion of the semiconductor region from the remainder of the semiconductor material, and enabling the MOS transistor to operate as an electrically isolated high-voltage I/O transistor for circuit noise reduction, while having low drain junction capacitance.

Abstract: A vertical bipolar transistor having low breakdown voltage, low ESD clamping voltage and high beta is fabricated in a semiconductor 301 of a first conductivity type, which has a buried layer 360 of the opposite conductivity type with sharp junctions, suitable as collector. This layer extends laterally to deep wells 371 of the opposite conductivity type, thus isolating the subsurface band 301a of the semiconductor of the first conductivity type. This band is suitable as the base and has a width 301c controlled by the proximity of the buried layer junction 360a. The emitter 310 is supplied by a surface region of the opposite conductivity type. The photomask, which is needed for implanting the low energy ions to create the extended emitter, is also used for the process step of implanting, at high energy and high dose, the ions needed (opposite conductivity type) to create the buried layer.

Abstract: A first fraction of a programming voltage is applied to a first word line coupled to a control gate of a selected ferroelectric memory cell in an array of ferroelectric memory cells. A gate/source voltage equal to the programming voltage is sufficient to reverse polarity of each memory cell. A ground potential is applied to other word lines coupled to control gates of non-selected memory cells. The first fraction of the programming voltage is applied to a first program line coupled to a first source/drain region of the selected memory cell and to other program lines coupled to first source/drain regions of non-selected memory cells. A second fraction of the programming voltage is applied to a first bit line coupled to a second source/drain region of the selected memory cell and to other bit lines coupled to second source/drain regions of non-selected memory cells.

Abstract: A programming voltage is applied to a first word line coupled to a control gate of a selected ferroelectric memory cell in an array of ferroelectric memory cells. A gate/source voltage equal to the programming voltage is sufficient to reverse polarity of each memory cell. A ground potential is applied to a first program line coupled to a first source/drain region of the selected memory cell and to a first bit line coupled to a second source/drain region of the selected memory cell. A fraction of the programming voltage is applied to other word lines coupled to control gates of non-selected memory cells not associated with the first word line, other program lines coupled to first source/drain regions of non-selected memory cells not associated with the first program line, and other bit lines coupled to second source/drain regions of non-selected memory cells not associated with the first bit line.

Abstract: An integrated circuit located between isolation trenches at the surface of a semiconductor chip comprising a first well of a first conductivity type having a first resistivity. This first well has a shallow buried region of higher resistivity than the first resistivity, extending between the isolation trenches and created by a compensating doping process. The circuit further comprises a second well of the opposite conductivity type extending to the surface between the isolation trenches, having a contact region and forming a junction with the shallow buried region of the first well, substantially parallel to the surface. Finally, the circuit has a MOS transistor located in the second well, spaced from the contact region, and having source, gate and drain regions at the surface. This space is predetermined to create a small voltage drop in I/O transistors for conditioning signals and power to a pad, or large voltage drops in ESD circuits for protecting the active circuitry connected to a pad.

Abstract: Depletion-mode ferroelectric transistors are adapted for use as non-volatile memory cells. Various embodiments have an array architecture such that two memory cells sharing the same bit line also share the same program line. Using this configuration, non-selected cells are readily supplied with gate/source voltages sufficient to maintain the cells in a deactivated state during read and write operations on selected cells.

Abstract: Bi-state ferroelectric-MOS (FMOS) capacitors are adapted for use in memory cells of a memory device. Bi-state ferroelectric memory cells have a bottom plate of a capacitor coupled to a first source/drain region of a pass transistor, a gate of the pass transistor coupled to a word line, and a second source/drain region of the pass transistor coupled to a bit line. A plate line is coupled to the top plate of the capacitor to facilitate programming of the polarization state of a ferroelectric portion of the capacitor. The polarization state of the ferroelectric portion of the capacitor causes a depletion or accumulation of electrons in the bottom plate of the capacitor, thus altering its capacitance value. The resulting capacitance value may be sensed without causing a polarization reversal of the ferroelectric portion of the capacitor. Accordingly, bi-state ferroelectric memory cells of the various embodiments function as non-volatile memory cells.

Abstract: Structure and fabrication method of a lateral MOS transistor, positioned on the surface of an integrated circuit fabricated in a semiconductor of a first conductivity type, comprising a source and a drain, each having at the surface a region of the opposite conductivity type extending to the centrally located gate, defining the active area of said transistor; and a semiconductor region within said semiconductor of the first conductivity type, having a resistivity higher than the remainder of the semiconductor, this region extending vertically below the transistor while laterally limited to the area of the transistor such that the resistivity under the gate is different from the resistivity under the source and drain regions.

Abstract: Structure and fabrication method of a lateral MOS transistor, positioned on the surface of an integrated circuit fabricated in a semiconductor of a first conductivity type, comprising a source and a drain, each having at the surface a region of the opposite conductivity type extending to the centrally located gate, defining the active area of said transistor; and a semiconductor region within said semiconductor of the first conductivity type, having a resistivity higher than the remainder of the semiconductor, this region extending vertically below the transistor while laterally limited to the area of the transistor such that the resistivity under the gate is different from the resistivity under the source and drain regions.

Abstract: An NMOS ESD clamping device and methods for making the same are disclosed in which the device includes N type drain and source regions formed in a semiconductor substrate and a gate overlying a P-type channel region in the substrate between the source and drain regions. A first silicide region is formed in the drain and/or the source region with a first thickness. A second thin silicide region is formed in the substrate between the gate and the drain having a second thickness less than the first thickness, wherein the thin silicide increases the ESD current clamping capability of the device to provide improved ESD circuit protection.

Abstract: Bi-state ferroelectric-MOS (FMOS) capacitors are adapted for use in memory cells of a memory device. Bi-state ferroelectric memory cells have a bottom plate of a capacitor coupled to a first source/drain region of a pass transistor, a gate of the pass transistor coupled to a word line, and a second source/drain region of the pass transistor coupled to a bit line. A plate line is coupled to the top plate of the capacitor to facilitate programming of the polarization state of a ferroelectric portion of the capacitor. The polarization state of the ferroelectric portion of the capacitor causes a depletion or accumulation of electrons in the bottom plate of the capacitor, thus altering its capacitance value. The resulting capacitance value may be sensed without causing a polarization reversal of the ferroelectric portion of the capacitor. Accordingly, bi-state ferroelectric memory cells of the various embodiments function as non-volatile memory cells.

Abstract: A vertical bipolar transistor having low breakdown voltage, low ESD clamping voltage and high beta is fabricated in a semiconductor 301 of a first conductivity type, which has a buried layer 360 of the opposite conductivity type with sharp junctions, suitable as collector. This layer extends laterally to deep wells 371 of the opposite conductivity type, thus isolating the subsurface band 301a of the semiconductor of the first conductivity type. This band is suitable as the base and has a width 301c controlled by the proximity of the buried layer junction 360a. The emitter 310 is supplied by a surface region of the opposite conductivity type.

Abstract: Depletion-mode ferroelectric transistors are adapted for use as non-volatile memory cells. Various embodiments are described having a diode interposed between the bit line and a source/drain region of the transistor for added margin against read disturb. Various additional embodiments are described having an array architecture such that two memory cells sharing the same bit line also share the same program line. Using this configuration, non-selected cells are readily supplied with gate/source voltages sufficient to maintain the cells in a deactivated state during read and write operations on selected cells.

Abstract: On the surface of a semiconductor material of a first conductivity type 101a, a lateral MOS transistor 100 is described surrounded by a well 171 of the opposite conductivity type and, nested within the well, an electrical isolation region 102. The semiconductor region 101a embedding this transistor has a resistivity higher than the remainder of the semiconductor material 101 and further contains a buried layer 160 of the opposite conductivity type. This layer 160 extends laterally to the wells 171, thereby electrically isolating the near-surface portion of the semiconductor region from the remainder of the semiconductor material, and enabling the MOS transistor to operate as an electrically isolated high-voltage I/O transistor for circuit noise reduction, while having low drain junction capacitance.

Abstract: Depletion-mode ferroelectric transistors are adapted for use as non-volatile memory cells. Various embodiments have an array architecture such that two memory cells sharing the same bit line also share the same program line. Using this configuration, non-selected cells are readily supplied with gate/source voltages sufficient to maintain the cells in a deactivated state during read and write operations on selected cells.