Abstract: A planar transistor with improved performance has a source and a drain on a semiconductor substrate that includes a substantially undoped channel extending between the source and the drain. A gate is positioned over the substantially undoped channel on the substrate. Implanted source/drain extensions contact the source and the drain, with the implanted source/drain extensions having a dopant concentration of less than about 1×1019 atoms/cm3, or alternatively, less than one-quarter the dopant concentration of the source and the drain.

Abstract: A method for fabricating a semiconductor structure so as to have reduced junction leakage is disclosed. The method includes providing substitutional boron in a semiconductor substrate. The method includes preparing the substrate using a pre-amorphization implant and a carbon implant followed by a recrystallization step and a separate defect repair/activation step. Boron is introduced to the pre-amorphized region preferably by ion implantation.

Abstract: Circuits, integrated circuits devices, and methods are disclosed that may include biasable transistors with screening regions positioned below a gate and separated from the gate by a semiconductor layer. Bias voltages can be applied to such screening regions to optimize multiple performance features, such as speed and current leakage. Particular embodiments can include biased sections coupled between a high power supply voltage and a low power supply voltage, each having biasable transistors. One or more generation circuits can generate multiple bias voltages. A bias control section can couple one of the different bias voltages to screening regions of biasable transistors to provide a minimum speed and lowest current leakage for such a minimum speed.

Abstract: A clock buffer circuit can include a low voltage drive circuit that receives a clock signal and provides a low voltage drive at a first power supply potential to a load. A boost drive circuit can provide a high voltage drive at a second power supply potential greater than the first power supply potential to the load. The boost drive circuit can provide the high voltage drive in response to a pulse signal generated in response to a transition of a clock input signal. A pulse generator circuit may generate the pulse signal to have a predetermined width to enable the high voltage drive until the load is charged essentially to the first power supply potential.

Abstract: A low voltage ring oscillator circuit can have a frequency variation that depends on process variations of insulated gate field effect transistors (IGFETs) of a first conductivity type without substantially being affected by process variations to IGFETs of a second conductivity type. A ring oscillator stage may include an inverter including only IGFETs of the first conductivity type. The inverter may be coupled to a boot circuit that boosts the gate potential of a first IGFET of the first conductivity type with a timing such that IGFETs of the second conductivity type in the boot circuit do not affect the frequency variations of the ring oscillator circuit.

Abstract: Some structures and methods to reduce power consumption in devices can be implemented largely by reusing existing bulk CMOS process flows and manufacturing technology, allowing the semiconductor industry as well as the broader electronics industry to avoid a costly and risky switch to alternative technologies. Some of the structures and methods relate to a Deeply Depleted Channel (DDC) design, allowing CMOS based devices to have a reduced sVT compared to conventional bulk CMOS and can allow the threshold voltage VT of FETs having dopants in the channel region to be set much more precisely. The DDC design also can have a strong body effect compared to conventional bulk CMOS transistors, which can allow for significant dynamic control of power consumption in DDC transistors. Additional structures, configurations, and methods presented herein can be used alone or in conjunction with the DDC to yield additional and different benefits.

Abstract: A semiconductor circuit can include an array of static random access memory (SRAM) cells. A first SRAM cell may provide a first current through an insulated gate field effect transistor (IGFET) having a first conductivity type. A second SRAM cell may provide a second current through an IGFET having a second conductivity type. A first current division slew circuit can provide a first slew output current proportional to the first current to change the charge on a first slew capacitor. A second current division slew circuit can provide a second slew output current proportional to the second current to change the charge on a second slew capacitor. A pulse may be generated having a first edge determined by a launch signal and a second edge determined by the time the first or the second capacitor reach a predetermined potential.

Abstract: An integrated circuit device can include at least a first bi-directional biasing circuit having a first substrate portion containing a plurality of first transistors; a first control digital-to-analog converter (DAC) to generate any of a plurality of first target values in response to a first target code; a first detect circuit configured to generate a difference value between the first target values and a first limit value; and at least a first charge pump circuit configured to drive the first substrate portion between a forward body bias voltage and a reverse body bias voltage for the first transistors in response to first target values. Embodiments can also include a performance monitor section configured to determine a difference between the voltage of the first substrate portion and a target voltage. Control logic can generate first code values in response to the difference between the voltage of the first substrate portion and the target voltage. Methods are also disclosed.

Abstract: A field effect transistor having a source, drain, and a gate can include a semiconductor substrate, a buried insulator layer positioned on the semiconductor substrate, and a semiconductor overlayer positioned on the buried insulator layer; a low dopant channel region positioned below the gate and between the source and the drain and in an upper portion of the semiconductor overlayer; and a plurality of doped regions having a predetermined dopant concentration profile, including a screening region positioned in the semiconductor overlayer below the low dopant channel region, the screening region extending toward the buried insulator layer, and a threshold voltage set region positioned between the screening region and the low dopant channel, the screening region and the threshold voltage set region having each a peak dopant concentration, the threshold voltage region peak dopant concentration being between 1/50 and ½ of the peak dopant concentration of the screening region.

Abstract: A method for fabricating field effect transistors using carbon doped silicon layers to substantially reduce the diffusion of a doped screen layer formed below a substantially undoped channel layer includes forming an in-situ epitaxial carbon doped silicon substrate that is doped to form the screen layer in the carbon doped silicon substrate and forming the substantially undoped silicon layer above the carbon doped silicon substrate. The method may include implanting carbon below the screen layer and forming a thin layer of in-situ epitaxial carbon doped silicon above the screen layer. The screen layer may be formed either in a silicon substrate layer or the carbon doped silicon substrate.

Abstract: Multiple transistor types are formed in a common epitaxial layer by differential out-diffusion from a doped underlayer. Differential out-diffusion affects the thickness of a FET channel, the doping concentration in the FET channel, and distance between the gate dielectric layer and the doped underlayer. Differential out-diffusion may be achieved by differentially applying a dopant migration suppressor such as carbon; differentially doping the underlayer with two or more dopants having the same conductivity type but different diffusivities; and/or differentially applying thermal energy.

Abstract: An integrated circuit can include a plurality of first transistors formed in a substrate and having gate lengths of less than one micron; and at least one tipless transistor formed in the substrate and having a source-drain path coupled between a circuit node and a first power supply voltage; wherein at least one tipless transistor has source and drain vertical doping profiles without extension regions that extend in a lateral direction under a gate electrode.

Abstract: A transistor and method of fabrication thereof includes a screening layer formed at least in part in the semiconductor substrate beneath a channel layer and a gate stack, the gate stack including spacer structures on either side of the gate stack. The transistor includes a shallow lightly doped drain region in the channel layer and a deeply lightly doped drain region at the depth relative to the bottom of the screening layer for reducing junction leakage current. A compensation layer may also be included to prevent loss of back gate control.

Abstract: Structures and processes are provided that can be used for effectively integrating different transistor designs across a process platform. In particular, a bifurcated process is provided in which dopants and other processes for forming some transistor types may be performed prior to STI or other device isolation processes, and other devices may be formed thereafter. Thus, doping and other steps and their sequence with respect to the STI process can be selected to be STI-first or STI-last, depending on the device type to be manufactured, the range of device types that are manufactured on the same wafer or die, or the range of device types that are planned to be manufactured using the same or similar mask sets.

Abstract: A method for modifying a design of an integrated circuit includes obtaining design layout data for the integrated circuit and selecting at least one SRAM cell in the integrated circuit to utilize enhanced body effect (EBE) transistors comprising a substantially undoped channel layer and a highly doped screening region beneath the channel layer. The method also includes extracting, from the design layout, NMOS active area patterns and PMOS active area patterns associated with the SRAM cell to define an EBE NMOS active area layout and a EBE PMOS active area layout. The method further includes adjusting the EBE NMOS active area layout to reduce a width of at least pull-down devices in the SRAM cell and altering a gate layer layout in the design layout data such that a length of pull-up devices in the at least one SRAM and a length of the pull-down devices are substantially equal.

Abstract: The effects of knock-on oxide in a semiconductor substrate are reduced by providing a semiconductor substrate and forming a thin layer of native oxide on the semiconductor substrate. Ion implantation is performed through the native oxide layer. The native oxide layer reduces the phenomenon of knock-on oxide and oxygen concentration within the semiconductor substrate. Further reduction may be achieved by etching the surface of the semiconductor substrate in order to eliminate a concentration of oxygen at a surface of the semiconductor substrate.

Abstract: Circuits are disclosed that may include a plurality of transistors having controllable current paths coupled between at least a first and second node, the transistors configured to generate an analog electrical output signal in response to an analog input value; wherein at least one of the transistors has a deeply depleted channel formed below its gate that includes a substantially undoped channel region formed over a relatively highly doped screen layer formed over a doped body region.

Abstract: A memory circuit device having at least one test element interconnecting memory sections can include at least one first switch coupled to a first memory section between a first node within a tested section and an intermediate node, a test switch coupled between the intermediate node and a forced voltage node, and a second switch coupled between the intermediate node and a second node; wherein the forced voltage node is selectively coupled to receive a forced voltage substantially the same as a voltage applied to the second node, and the second node is coupled to at least a second memory section.

Abstract: An analog transistor useful for low noise applications or for electrical circuits benefiting from tight control of threshold voltages and electrical characteristics is described. The analog transistor includes a substantially undoped channel positioned under a gate dielectric between a source and a drain with the undoped channel not being subjected to contaminating threshold voltage implants or halo implants.

Abstract: An integrated circuit can include an operational section comprising a first body bias circuit coupled to drive first body regions to a first bias voltage in response to at least first bias values; a second body bias circuit coupled to drive second body regions to a second bias voltage in response to at least second bias values; a plurality of monitoring sections formed in a same substrate as the operational section, each configured to output a monitor value reflecting a different process variation effect on circuit performance.