International Business Machines Corporation

Peter Edwin Cottrell

Edward J Nowak

Andres Bryant

Robert J Gauthier, Jr

Jed Hickory Rankin

Fariborz Assaderaghi

John J Ellis-Monaghan

Kerry Bernstein

Norman Jay Rohrer

Ronald R Troutman

Wilbur David Pricer

Stephen Victor Kosonocky

Randy William Mann

John E Gersbach

Henry J Geipel, Jr

William J Craig

Robert H Dennard

Kevin John Nowka

Mark B Ketchen

Douglas Willard Stout

David Meltzer

Roger Paul Gregor

Donald McAlpine Kenney

A semiconductor memory device comprising: an SOI substrate having a thin silicon layer on top of a buried insulator; and an SRAM comprising four NFETs and two PFETs located in the thin silicon layer, each the NFET and PFET having a body region between a source region and a drain region, wherein the bodies of two of the NFETs are electrically connected to ground. Additionally, the bodies of the two PFETs are electrically connected to V.

Grounded body SOI SRAM cell

A radiation detector formed using silicon-on-insulator technology. The radiation detector includes a silicon layer formed on an insulating substrate, wherein the silicon layer includes a PNPN structure, and a gate layer formed over the PNPN structure, wherein the gate layer includes a PN gate. Latch-up occurs in the radiation detector only in response to incident radiation.

Silicon-on-insulator latch-up pulse-radiation detector

A body contact structure utilizing an insulating structure between the body contact portion of the active area and the transistor portion of the active area is disclosed. In one embodiment, the present invention substitutes an insulator for at least a portion of the gate layer in the regions between the transistor and the body contact. In another embodiment, a portion of the gate layer is removed and replaced with an insulative layer in regions between the transistor and the body contact. In still another embodiment, the insulative structure is formed by forming multiple layers of gate dielectric between the gate and the body in regions between the transistor and the body contact. The body contact produced by these methods adds no significant gate capacitance to the gate.

Body contact MOSFET

A semiconductor memory device comprising: an SOI substrate having a thin silicon layer on top of a buried insulator; and an SRAM comprising four NFETs and two PFETs located in the thin silicon layer, each the NFET and PFET having a body region between a source region and a drain region, wherein the bodies of two of the NFETs are electrically connected to ground. Additionally, the bodies of the two PFETs are electrically connected to V .

An apparatus for biasing ultra-low voltage logic circuits is disclosed. An integrated circuit device includes multiple transistors and a global body bias circuit. The global body bias circuit includes a first transistor and second transistors connected in series between a power supply and a second power supply or ground. The gate and source of the first transistor are connected to the first power supply. The gate and source of the second transistor are connected to the second power supply. The drains and bodies of the first and second transistors are connected together to form an output connected to the bodies of the other transistors within the integrated circuit device.

Apparatus for biasing ultra-low voltage logic circuits

A differential logic circuit ( and ) designed to ensure stability of the output of the circuit. The logic circuit includes a differential load structure ( ) that is connected to evaluate transistors ( ). In several embodiments, the outputs of the load transistors ( ) in the differential load structure are connected to the bodies of the evaluate transistors. In the other embodiments, the outputs of the load transistors in the differential structure are connected to one of the gates of a double-gated evaluate transistors. Level-shifting output buffers ( ) are used in connection with the embodiments of the invention that do not include double-gated evaluate transistors.

Body-contacted and double gate-contacted differential logic circuit and method of operation

A circuit includes a resistance-capacitance (RC) structure connected to a first set of transistors and a second set of transistors that perform the same logical function as the first set of transistors. The first set of transistors have thinner gate oxides than the second set of transistors. The RC structure drains an electric field from the first set of transistors, such that the first set of transistors are on only during initial transistor switching. In other words, the RC structure turns off the first set of transistors after transistor switching is completed. Also, the first set of transistors and the second set of transistors share common inputs and outputs. The first set of transistors exhibit higher tunneling currents than the second set of transistors. The thinner gate oxides of the first set of transistors cause the first set of transistors to exhibit higher device currents than the second set of transistors. The RC structure includes a capacitor connected to a gate of the first set of transistors and a resistor connected to the capacitor and to ground.

Transient gate tunneling current control

A system and method for achieving self-regulated voltage division among multiple serially stacked voltage planes. The system of the present invention is incorporated within a source voltage plane having a source supply node for supplying current and a source ground node for sinking current supplied therefrom. An intermediate voltage supply node is coupled between the source supply voltage node and the source ground node for dividing the source voltage plane into a plurality of intermediate voltage planes. The self-regulated voltage divider of the present invention includes a first capacitor and a second capacitor that are each controllably coupled between either the source supply voltage node and the intermediate voltage supply node, or between the intermediate voltage supply node and the source ground node, such that a voltage level balance is achieved among the intermediate voltage planes.

Self-regulating voltage divider for series-stacked voltage rails

This invention provides a differential circuit having first and second transistors interconnected by a third transistor which is symmetrically constructed. A current source is selectively connected to the base of the third transistor. When the current source is connected to the base of the third transistor, the third transistor is saturated, forming a very low impedance path between the first and second transistors. However, when the current source is disconnected from the base of the third transistor, the third transistor impedes the voltage breakdown path between the bases of the first and second transistors. The differential circuit is particularly useful in an improved compact magnetic media system wherein both the stored signal and the write signal or voltage are applied to the bases of the first and second transistor of the circuit without the high write voltages destroying the high performance first and second transistors.

Differential circuit having a high voltage switch

A charge pumping structure is disclosed for use in a substrate bias voltage generator. It includes a capacitor on a substrate region for coupling to a first node periodic voltage signals received at a second node. A first diode structure provides a current path from the first node to the substrate and a second diode structure provides a current path between the first node and a reference potential, which is typically the ground. The first diode structure includes a PN junction diode, an isolation ring for collecting minority charge carriers injected into the substrate and is constructed on a portion of the substrate that has a lower doping concentration than the underlying substrate portion establishing a built-in electric field which inhibits the flow of minority carriers from the first diode to the underlying substrate. The second diode structure may include a pocket type PN junction diode constructed so that majority carriers are prevented from moving back into the substrate from which the substrate bias voltage generator will have to remove them.

Charge pumping structure for a substrate bias generator

Disclosed is an overvoltage protection structure which when used with CMOS circuits it protects them from overvoltage conditions while minimizing latch-up conditions in the structure. It consists of a well region of an opposite conductivity to that of the substrate defining a pocket region having a conductivity type which is similar to that of the substrate. A first PN junction diode is formed in a portion of the well region and a second PN junction diode is formed in the pocket region. The two diodes have opposite polarity and they both are connected to a signal line in such a way that one of the two diodes will be forward biased if the voltage on the signal line exceeds the bounds of the power supply voltages. The pocket region is connected to a V.sub.SS terminal which is normally grounded and the well region is connected to a power supply V.sub.DD. The doping concentration in the well region is predetermined to have a gradient so that minority carriers injected from one of the diodes in the well region will be repulsed and prevented from moving into the substrate region where they would be majority carriers and they could cause latch-up in the structure or at the very least adversely affect the voltage level of the substrate. Instead the injected carriers recombine in the well region or are collected by the adjacent isolated pocket region. When the second diode is forward biased, the minority carriers are injected into the isolated pocket region and are prevented from reaching the substrate by the underlying well region. This prevents these carriers from affecting the operation of adjacent circuits.

Twin diode overvoltage protection structure

A very simple process is provided, with reduced processing time, for making a CMOS structure using a single polysilicon, or other refractory metal, layer which includes forming a thin gate oxide on both N and P type semiconductor layers of a common substrate, forming a gate electrode simultaneously on the N type and on the P type layers and selectively implanting an N type impurity to form N+ source and drain regions in the P type layer. The semiconductor layers are then oxidized to form substantially thicker oxide, such a silicon dioxide, adjacent to the sides of the gate electrode over the P type layer than the thickness of the oxide adjacent to the sides of the gate electrode over the N type layer. Without using a mask, a P type impurity is implanted into the N type layer to form P+ source and drain regions.

Simple process for making complementary transistors

This invention provides an amplifier circuit having first and second transistors interconnected by a third transistor which is symmetrically constructed. A current source is selectively connected to the base of the third transistor. When the current source is connected to the base of the third transistor, the third transistor is saturated, forming a very low impedance path between the first and second transistors. However, when the current source is disconnected from the base of the third transistor, the third transistor impedes the voltage breakdown path between the bases of the first and second transistors. The amplifier circuit is particularly useful in an improved compact magnetic media system wherein both the stored signal and the write signal or voltage are applied to the bases of the first and second transistor of the amplifier without the high write voltages destroying the high performance first and second transistors.

Sensitive amplifier having a high voltage switch

A simple process is provided for making a planar CMOS structure wherein isolation regions required by bulk CMOS structures are first formed, an N channel device field region is self-aligned to an N well region in a semiconductor substrate and a refractory material is twice defined for forming P and N channels, the first definition masking P channel source and drain regions while defining the N channel and the second definition defining the P channel while using a photoresist layer to mask the N channel. In the process, a technique which uses a single mask level defines the well region and self-aligns the necessary field doping to the well region to provide closely spaced N and P channel devices.

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Essex Junction, VT, United States of America

Peter Edwin Cottrell