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Showing papers on "Biasing published in 2004"


Proceedings ArticleDOI
13 Dec 2004
TL;DR: In this article, a simple binary transition metal oxide (TMO) resistive random access memory (RRAM) was integrated with 0.18/spl mu/m CMOS technology, and its device as well as cell properties were reported for the first time.
Abstract: Simple binary-TMO (transition metal oxide) resistive random access memory named as OxRRAM has been fully integrated with 0.18/spl mu/m CMOS technology, and its device as well as cell properties are reported for the first time. We confirmed that OxRRAM is highly compatible with the conventional CMOS process such that no other dedicated facility or process is necessary. Filamentary current paths, which are switched on or off by asymmetric unipolar voltage pulses, made the cell properties insensitive to cell or contact size promising high scalability. Also, OxRRAM showed excellent high temperature performance, even working at 300/spl deg/C without any significant degradation. With optimized TMO material and electrodes, OxRRAM operated successfully under 3V bias voltage and 2mA switching current at a TMO cell size smaller than 0.2/spl mu/m/sup 2/.

672 citations


Patent
24 Aug 2004
TL;DR: In this paper, a method for making a laser driver circuit for burst mode is described, which includes the following steps: First, a continuous mode laser driver is selected, the chip having a temperature compensation output, a bias current setting input, and a reference current setting output.
Abstract: A method for making a laser driver circuit for burst mode is described. The method includes the following steps: First, a continuous mode laser driver circuit is selected, the chip having a temperature compensation output, a bias current setting input, and a reference current setting input. Next, the temperature compensation signal is converted to a reference current setting signal via a first bias adjustment circuit, and the reference current setting signal is input to the reference current setting input. Then, the bias current setting input is connected to ground via a second bias adjustment circuit. The reference current setting signal automatically adjusts the high level and the low level of the eye diagram of the laser according to the environmental temperature, so that the high level and the low level are kept stable to reduce the bit error rate in transmission.

597 citations


Journal ArticleDOI
TL;DR: In this article, the internal resistance in a dye-sensitized solar cell (DSC) was investigated using electrochemical impedance spectroscopy measurements, and an equivalent circuit for DSCs was proposed based on these results.
Abstract: Internal resistance in a dye-sensitized solar cell (DSC) was investigated using electrochemical impedance spectroscopy measurements. Four resistance elements were observed in the impedance spectra, and their dependencies on the applied bias voltage were characterized. It is found that the resistance element related to charge transport at the TiO2/dye/electrolyte interface displays behavior like that of a diode, and the series resistance elements largely correspond to the sum of the other resistance elements. An equivalent circuit for DSCs is proposed based on these results.

590 citations


Journal ArticleDOI
13 Dec 2004
TL;DR: In this article, a metamaterial-based electronically controlled transmission line structure is presented and demonstrated as a novel leaky-wave (LW) antenna with tunable radiation angle and beamwidth functionalities.
Abstract: A metamaterial-based electronically controlled transmission-line structure is presented and demonstrated as a novel leaky-wave (LW) antenna with tunable radiation angle and beamwidth functionalities. This structure is, in essence, a composite right/left-handed (CRLH) microstrip structure incorporating varactor diodes for fixed-frequency voltage-controlled operation. Angle scanning at a fixed frequency is achieved by modulating the capacitances of the structure by adjusting the (uniform) bias voltage applied to the varactors. Beamwidth tuning is obtained by making the structure nonuniform by application of a nonuniform bias voltage distribution of the varactors. A rigorous analysis based on an extension of the CRLH concept is proposed and the corresponding dispersion curves, obtained by equivalent-circuit formulas with LC parameters extracted from full-wave simulation, are shown. A 30-cell LW antenna structure, incorporating both series and shunt varactors for optimal impedance matching and maximal tuning range, is designed. This prototype exhibits continuous scanning capability from 50/spl deg/ to -49/spl deg/ by tuning the bias voltages from 0 to 21 V at 3.33 GHz. A maximum gain of 18 dBi at broadside is also achieved. In addition, it provides half-power beamwidth variation of up to 200% with comparison to the case of uniform biasing. The effect of intermodulation due to the nonlinearity of the varactors is shown to be negligible for antenna applications. The antenna is tested in a 10-Mb/s binary phase-shift keying transmission link and successful recovery of the baseband data is demonstrated.

532 citations


Journal ArticleDOI
TL;DR: A pH sensor fabricated on a single chip by an unmodified, commercial 0.6-/spl mu/m CMOS process is presented in this article, which comprises a circuit for making differential measurements between an ion-sensitive field effect transistor (ISFET) and a reference FET (this articleET).
Abstract: A pH sensor fabricated on a single chip by an unmodified, commercial 0.6-/spl mu/m CMOS process is presented. The sensor comprises a circuit for making differential measurements between an ion-sensitive field-effect transistor (ISFET) and a reference FET (REFET). The ISFET has a floating-gate structure and uses the silicon nitride passivation layer as a pH-sensitive insulator. As fabricated, it has a large threshold voltage that is postulated to be caused by a trapped charge on the floating gate. Ultraviolet radiation and bulk-substrate biasing is used to permanently modify the threshold voltage so that the ISFET can be used in a battery-operated circuit. A novel post-processing method using a single layer of photoresist is used to define the sensing areas and to provide robust encapsulation for the chip. The complete circuit, operating from a single 3-V supply, provides an output voltage proportional to pH and can be powered down when not required.

185 citations


Proceedings ArticleDOI
23 May 2004
TL;DR: A novel bias circuit is proposed to generate the gate voltage for zero 3rd-order nonlinearity of the FET transconductance and measured data show that a peak in IIP/sub 3/ occurs at a gate voltage slightly different from the one predicted by the dc theory.
Abstract: A FET linearization technique based on optimum gate biasing is investigated at RF. A novel bias circuit is proposed to generate the gate voltage for zero 3rd-order nonlinearity of the FET transconductance. The measured data show that a peak in IIP/sub 3/ occurs at a gate voltage slightly different from the one predicted by the dc theory. The origins of this offset are explained based on a Volterra series analysis and confirmed experimentally. The technique was used in a 0.25 /spl mu/m CMOS cellular-band CDMA LNA. At the optimum bias, the amplifier achieved a NF of 1.8 dB, an IIP/sub 3/ of +10.5 dBm, and a power gain of 14.6 dB with a current consumption of only 2 mA from 2.7 V supply.

140 citations


Journal ArticleDOI
TL;DR: The direct impact of the electronic structure on spin-polarized transport has been experimentally proven in high-quality Fe/MgO/Fe epitaxial magnetic tunnel junctions, with an extremely flat bottom Fe/ MgO interface.
Abstract: The direct impact of the electronic structure on spin-polarized transport has been experimentally proven in high-quality Fe/MgO/Fe epitaxial magnetic tunnel junctions, with an extremely flat bottom Fe/MgO interface. The voltage variation of the conductance points out the signature of an interfacial resonance state located in the minority band of Fe(001). When coupled to a metallic bulk state, this spin-polarized interfacial state enhances the band matching at the interface and therefore increases strongly the conductivity in the antiparallel magnetization configuration. Consequently, the tunnel magnetoresistance is found to be positive below 0.2 V and negative above. On the other hand, when the interfacial state is either destroyed by roughness-related disorder or not coupled to the bulk, the magnetoresistance is almost independent on the bias voltage.

125 citations


Journal ArticleDOI
TL;DR: In this article, the authors observed a shift in the magnetic hysteresis loop of the LSMO layer in the same direction as the applied biasing field (positive exchange bias).
Abstract: Epitaxial La0.67Sr0.33MnO3(LSMO)∕SrRuO3(SRO) ferromagnetic bilayers have been grown on (001)SrTiO3(STO) substrates by pulsed laser deposition with atomic layer control. We observe a shift in the magnetic hysteresis loop of the LSMO layer in the same direction as the applied biasing field (positive exchange bias). The effect is not present above the Curie temperature of the SRO layer (TcSRO), and its magnitude increases rapidly as the temperature is lowered below TcSRO. The direction of the shift is consistent with an antiferromagnetic exchange coupling between the ferromagnetic LSMO layer and the ferromagnetic SRO layer. We propose that atomic layer charge transfer modifies the electronic state at the interface, resulting in the observed antiferromagnetic interfacial exchange coupling.

123 citations


Journal ArticleDOI
TL;DR: In this article, the magnetic field behavior of the off-diagonal impedance in Co-based amorphous wires under sinusoidal (50 MHz) and pulsed (5 ns rise time) current excitations was investigated.
Abstract: We investigated the magnetic-field behavior of the off-diagonal impedance in Co-based amorphous wires under sinusoidal (50 MHz) and pulsed (5 ns rise time) current excitations. For comparison, we measured the field characteristics of the diagonal impedance as well. In general, when an alternating current is applied to a magnetic wire, the voltage signal is generated not only across the wire but also in a pickup coil wound on it. These voltages are related to the diagonal and off-diagonal impedances, respectively. We demonstrate that these impedances have a different behavior as functions of axial magnetic field: the diagonal impedance is symmetrical, whereas the off-diagonal one is antisymmetrical with a near-linear portion within a certain field interval. For the off-diagonal response, the dc bias current is necessary to eliminate circular domains. In the case of the sinusoidal excitation without a dc bias current, the off-diagonal response is very small and irregular. In contrast, the pulsed excitation, combining both high- and low-frequency harmonics, produces the off-diagonal voltage response without additional biasing. This behavior is ideal for a practical sensor circuit design. We discuss the principles of operation of a linear magnetic sensor based on a complementary metal-oxide-semiconductor transistor circuit.

121 citations


Journal ArticleDOI
TL;DR: In this article, the authors used X-ray photoelectron spectroscopy to examine the chemical nature of titanium nitride (TiN) films deposited by reactive unbalanced magnetron sputtering under different substrate biases (ranging from 0 to −500 V).
Abstract: X-ray photoelectron spectroscopy has been used to examine the chemical nature of titanium nitride (TiN) films deposited by reactive unbalanced magnetron sputtering under different substrate biases (ranging from 0 to −500 V). Before Ar+ sputtering, three groups of Ti 2p doublet, related to TiN, TiON and TiO2, were observed in the core level spectra of the deposited TiN films. The intensity of peak from TiO2 decreases drastically with the increasing substrate bias, reaching a minimum at a bias voltage of –100 V, and then increases greatly. However, the intensity of peak from TiN shows an opposite behavior with its maximum value at –100 V. Furthermore, the nonlinear intensity variation of these peaks was accompanied with obvious nonlinear trend of peak shift. Similar tendency was found for the N 1 s spectra of these films. After Ar+ sputtering, the Ti 2p and N 1 s region of bulk TiN both displayed a nonlinear peak shifting with their highest binding energy at a bias voltage of –50 V. The reason for the different optimum bias between the surface and the bulk were considered to be the incorporation and diffusion of oxygen near surface. The appropriate substrate bias was believed to be helpful for the bonding and formation of stoichiometric TiN, hinder the generation of surface oxide and restrict the initiation of impurities and defects in both surface and bulk materials. Our atomic force microscopy study also revealed a nonlinear trend of surface morphology and root-mean-square roughness. As a combined effect from improved surface morphology, significantly restricted surface oxidation and well-bonded stoichiometric TiNx in both native surface and bulk material, the best hardness was measured to be about 32 GPa at optimum bias of –100 V.

120 citations


Journal ArticleDOI
TL;DR: This system provides a unique example of reversible assembly of nanostructures at interfaces, in which the density can be effectively tuned by the applied potential bias.
Abstract: The voltage-induced assembly of mercaptosuccinic acid-stabilized Au nanoparticles of 1.5 ± 0.4 nm diameter is investigated at the polarizable water|1,2-dichloroethane interface. Admittance measurements and quasi-elastic laser scattering (QELS) studies reveal that the surface concentration of the nanoparticle at the liquid|liquid boundary is reversibly controlled by the applied bias potential. The electrochemical and optical measurements provide no evidence of irreversible aggregation or deposition of the particles at the interface. Analysis of the electrocapillary curves constructed from the dependence of the frequency of the capillary waves on the applied potential and bulk particle concentration indicates that the maximum particle surface density is 3.8 × 1013cm-2, which corresponds to 67% of a square closed-pack arrangement. This system provides a unique example of reversible assembly of nanostructures at interfaces, in which the density can be effectively tuned by the applied potential bias.

Journal ArticleDOI
TL;DR: In this paper, the magnetic field behavior of the off-diagonal impedance in Co-based amorphous wires is investigated under the condition of sinusoidal (50 MHz) and pulsed (5 ns rising time) current excitations.
Abstract: The magnetic-field behaviour of the off-diagonal impedance in Co-based amorphous wires is investigated under the condition of sinusoidal (50 MHz) and pulsed (5 ns rising time) current excitations. For comparison, the field characteristics of the diagonal impedance are measured as well. In general, when an alternating current is applied to a magnetic wire the voltage signal is generated not only across the wire but also in the coil mounted on it. These voltages are related with the diagonal and off-diagonal impedances, respectively. It is demonstrated that these impedances have a different behaviour as a function of axial magnetic field: the former is symmetrical and the latter is antisymmetrical with a near linear portion within a certain field interval. In the case of the off-diagonal response, the dc bias current eliminating circular domains is necessary. The pulsed excitation that combines both high and low frequency harmonics produces the off-diagonal voltage response without additional bias current or field. This suits ideal for a practical sensor circuit design. The principles of operation of a linear magnetic sensor based on C-MOS transistor circuit are discussed.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the properties of tunneling magnetoresistance (TMR) of (Ga,Mn)As trilayer structures with a GaAs intermediary barrier layer.
Abstract: We have investigated the properties of tunneling magnetoresistance (TMR) of (Ga,Mn)As trilayer structures with a GaAs intermediary barrier layer. TMR ratio of 290% is observed at 0.39 K around zero applied bias voltage. The bias dependence of TMR ratio as well as the temperature-dependent anisotropic behavior are presented.

Journal ArticleDOI
TL;DR: In this paper, a Ga 2 O 3/SiC metal-reactive insulator-silicon carbide (MRISiC) sensor with spin-coating was developed for hydrogen gas sensitivity.
Abstract: Pt/Ga 2 O 3 /SiC metal-reactive insulator-silicon carbide (MRISiC) devices operated as Schottky diodes were characterized for their hydrogen gas sensitivity. The sensors have been tested towards different concentrations of hydrogen gas as a function of operating temperature. This study shows advantages of this structure compared to the pure thin film (90 nm) Ga 2 O 3 conductometric sensor. The Ga 2 O 3 thin films were prepared by the sol–gel process and deposited onto the transducers by spin-coating. For both types of sensors, the operating temperature was controlled by a micro heater located beneath the structure. It was found that cycling the ambient from synthetic air (SA) to 1% H 2 in SA air produces repeatable changes of the forward voltage at fixed forward bias. At high temperature (above 500 °C), the response time of the sensors decreases. Furthermore, the sensor shows remarkable stability and the decrease in bias voltage subject to 1% H 2 was 210 mV.

Journal ArticleDOI
TL;DR: In this article, an orientation-dependent wet-etching technique was used to verify the controllability of high threshold voltage (V/sub th/)-controllable four-terminal (4T) FinFETs with an aggressively thinned Si-fin thickness.
Abstract: Highly threshold voltage (V/sub th/)-controllable four-terminal (4T) FinFETs with an aggressively thinned Si-fin thickness down to 8.5-nm have successfully been fabricated by using an orientation-dependent wet-etching technique, and the V/sub th/ controllability by gate biasing has systematically been confirmed. The V/sub th/ shift rate (/spl gamma/=-/spl delta/V/sub th///spl delta/V/sub g2/) dramatically increases with reducing Si-fin thickness (T/sub Si/), and the extremely high /spl gamma/=0.79 V/V is obtained at the static control gate bias mode for the 8.5-nm-thick Si-fin channel device with the 1.7-nm-thick gate oxide. By the synchronized control gate driving mode, /spl gamma/=0.46 V/V and almost ideal S-slope are achieved for the same device. These experimental results indicate that the optimum V/sub th/ tuning for the high performance and low-power consumption very large-scale integrations can be realized by a small gate bias voltage in the ultrathin Si-fin channel device and the orientation-dependent wet etching is the promising fabrication technique for the 4T FinFETs.

Journal ArticleDOI
Hidefumi Hiura1
TL;DR: In this article, a scanning tunneling microscope (STM) was used to tailor graphite surface from one to several layers in depth using water-adsorbed graphite surfaces.

Patent
08 Jul 2004
TL;DR: In this article, an electro-optical device includes a plurality of pixel circuits each including a light-emitting element and a driving transistor for driving the light emitting element; data lines that are connected to the plurality of pixels and that supply data signals representing light emitting gray-scale levels to the pixel circuits; and a data line driving circuit that supplies the data signals to the pixels through the data lines.
Abstract: An electro-optical device includes a plurality of pixel circuits each including a light-emitting element and a driving transistor for driving the light-emitting element; data lines that are connected to the plurality of pixel circuits and that supply data signals representing light-emitting gray-scale levels to the pixel circuits; and a data line driving circuit that supplies the data signals to the pixel circuits through the data lines. In addition, the data line driving circuit applies to each pixel circuit in a predetermined sequence a forward frame period supplying a data signal having a forward bias voltage for making the light-emitting element emit light and a backward frame period supplying a data signal having a backward bias voltage for making the light-emitting element not emit light, and drives each of the pixel circuits.

Journal ArticleDOI
TL;DR: In this article, a model for the electron injection mechanism in a p-type organic transistor was proposed, and the dependence of the external quantum efficiency on drain-and gate-bias was investigated.

Journal ArticleDOI
TL;DR: In this paper, high-quality heterojunctions between p-type diamond single-crystalline films and highly oriented n-type ZnO films were fabricated by depositing the p type diamond singlecrystal films on the Io-type single crystal using a hot filament chemical vapor deposition.
Abstract: High-quality heterojunctions between p-type diamond single-crystalline films and highly oriented n-type ZnO films were fabricated by depositing the p-type diamond single-crystal films on the Io-type diamond single crystal using a hot filament chemical vapor deposition, and later growing a highly oriented n-type ZnO film on the p-type diamond single-crystal film by magnetron sputtering. Interestingly, anomalously high ideality factors (n≫2.0) in the prepared ZnO/diamond p–n junction diode in the interim bias voltage range were measured. For this, detailed electronic characterizations of the fabricated p–n junction were conducted, and a theoretical model was proposed to clarify the much higher ideality factors of the special heterojunction diode.

Journal ArticleDOI
TL;DR: An oxide bilayer junction has been fabricated by growing a La0.32Pr0.35Ca0.33MnO3 film on 0.5 wt % Nb-doped SrTiO3 crystal as discussed by the authors.
Abstract: An oxide bilayer junction has been fabricated by growing a La0.32Pr0.35Ca0.33MnO3 film on 0.5 wt % Nb-doped SrTiO3 crystal, and its behavior under magnetic field is experimentally studied. It is found that external field greatly affected the rectifying property and the resistance of the junction, causing an extremely large magnetoresistance. The most striking observation of the present work is that the magnetoresistance of the junction can be either positive or negative, depending on temperature and applied current, and is asymmetric with respect to the direction of the bias current. These results reveal the great potential of the manganites in configuring artificial devices.

Patent
23 Jun 2004
TL;DR: In this article, a method and apparatus for controlling conduction between two nodes of an integrated circuit via a stack of FETs of common polarity, coupled in series, is described.
Abstract: A method and apparatus is described for controlling conduction between two nodes of an integrated circuit via a stack of FETs of common polarity, coupled in series. In an RF Power Amplifier (PA) having appropriate output filtering, or in a quad mixer, stacks of two or more FETs may be used to permit the use of increased voltages between the two nodes. Power control for such RF PAs may be effected by varying a bias voltage to one or more FETs of the stack. Stacks of three or more FETs may be employed to control conduction between any two nodes of an integrated circuit.

Journal ArticleDOI
TL;DR: In this paper, it was shown that pulsing the target voltage can strongly influence these intrinsic parameters and can cause much greater energy fluxes to be delivered to the substrate than in DC systems operating at the same input power.
Abstract: In magnetron sputtering, coating properties are largely determined by the rate at which energy is delivered to the growing film through simultaneous ion bombardment. The structure and properties depend on three parameters: the homologous temperature; the ratio of the fluxes of bombarding ions and depositing atoms; and the energy of the bombarding ions. It is shown here that pulsing the target voltage can strongly influence these intrinsic parameters and can cause much greater energy fluxes to be delivered to the substrate than in DC systems operating at the same input power. Time averaged Langmuir probe measurements have shown that electron temperatures, ion and electron densities and ion fluxes to the substrate all increase with increasing pulse frequency, and that a burst of “hot” electrons is associated with the fast negative voltage transient between “reverse” and “on” phases of the target voltage. It is shown that the energies of the ions arriving at the substrate are influenced by both the reverse time/duty factor and the pulse frequency, and that that these energy variations have very significant effects on coating structure and properties. The effects of applying mid-frequency (100–350 kHz) pulsed dc power at the substrate have also been studied. It has been found that, unlike the dc case, if the bias is pulsed in this range, the current drawn at the substrate does not saturate, but continues to increase with increasing bias voltage. In addition, this effect becomes more marked as the pulse frequency is increased. Pulsing the substrate bias voltage, therefore, offers a novel means of controlling the ion current drawn at the substrate. Clearly, this has significant implications in relation to film growth, sputter cleaning, and substrate preheating processes.

Proceedings ArticleDOI
13 Sep 2004
TL;DR: In this article, a lowvoltage swapped-body biasing technique where PMOS bodies are connected to ground and NMOS bodies to VCC is evaluated, and the results show more than 2.6x frequency improvement at 0.5V VCC and the ability to reduce Vcc by 0.2V for the same frequency compared to no body bias in 180 to 90nm CMOS technologies.
Abstract: A low-voltage swapped-body biasing technique where PMOS bodies are connected to ground and NMOS bodies to Vcc is evaluated. Available measurements show more than 2.6x frequency improvement at 0.5V Vcc and the ability to reduce Vcc by 0.2V for the same frequency compared to no body bias in 180 to 90nm CMOS technologies.

Journal ArticleDOI
TL;DR: The high-bias transport properties of the different shells that constitute a multiwalled carbon nanotube are studied and the current is shown to be reduced as the shell diameter is decreased or the length is increased.
Abstract: We have studied the high-bias transport properties of the different shells that constitute a multiwalled carbon nanotube. The current is shown to be reduced as the shell diameter is decreased or the length is increased. We assign this geometrical dependence to the competition between the electron-phonon scattering process and Zener tunneling.

Journal ArticleDOI
TL;DR: In this article, epitaxial trilayer films of cobalt-phthalocyanine (CoPc) were studied on Au(1/1/3) 22×3 surfaces using a scanning tunneling microscope at 78 K.

Journal ArticleDOI
TL;DR: In this paper, the electrical and optical properties of a silicon electro-optic waveguide modulator using a metal-oxide-semiconductor (MOS) configuration were analyzed.
Abstract: We analyze the electrical and optical properties of a silicon electro-optic waveguide modulator using a metal-oxide-semiconductor (MOS) configuration. The device performance is studied under different modes of operation of the MOS diode and gate oxide thicknesses. Our calculations indicate that this scheme can be used for achieving high-speed submicron waveguide active devices on silicon on insulator. A microring resonator intensity modulator is predicted to exhibit switching times on the order of tens of picoseconds with modulation depth of 73% by employing a bias voltage of only 5 V.

Patent
11 May 2004
TL;DR: In this paper, a micro-gyroscope (10) having closed loop output operation by a control voltage (Vty), that is demodulated by a drive axis (x-axis) signal Vthx of the sense electrodes (S1, S2), providing Coriolis torque rebalance to prevent displacement of the micro gyroscope on the output axis (y-axis), Vthy˜0.
Abstract: A micro-gyroscope (10) having closed loop output operation by a control voltage (Vty), that is demodulated by a drive axis (x-axis) signal Vthx of the sense electrodes (S1, S2), providing Coriolis torque rebalance to prevent displacement of the micro-gyroscope (10) on the output axis (y-axis) Vthy˜0. Closed loop drive axis torque, Vtx maintains a constant drive axis amplitude signal, Vthx. The present invention provides independent alignment and tuning of the micro-gyroscope by using separate electrodes and electrostatic bias voltages to adjust alignment and tuning. A quadrature amplitude signal, or cross-axis transfer function peak amplitude is used to detect misalignment that is corrected to zero by an electrostatic bias voltage adjustment. The cross-axis transfer function is either Vthy/Vty or Vtnx/Vtx. A quadrature signal noise level, or difference in natural frequencies estimated from measurements of the transfer functions is used to detect residual mistuning, that is corrected to zero by a second electrostatic bias voltage adjustment.

Patent
02 Mar 2004
TL;DR: In this paper, the body bias voltage of an nFET was used to maintain the ratio of ION/IOFF at B/A for some range of temperatures, where ION is a transistor current when ON and IOFF is a leakage current when OFF.
Abstract: Embodiments circuits provide a transistor body bias voltage so that the ratio of ION to IOFF is constant over a range of temperature, where ION is a transistor current when ON and IOFF is a (leakage) transistor current when OFF. In one embodiment, a nFET is biased to provide ION to a current mirror that sources a current AION to a node, a nFET is biased to provide IOFF to a current mirror that sinks a current BIOFF from the node, and an amplifier provides feedback from the node to the body terminals of the nFETs so that at steady state AION=BIOFF, where A and B are constants independent over a range of temperature. In this way, the ratio ION/IOFF is maintained at B/A for some range of temperatures. Other embodiments are described and claimed.

Journal ArticleDOI
TL;DR: In this paper, thin film capacitors of Al/Sm 2 O 3 /Al structure have been prepared by vacuum evaporation and their structural and optical properties have been obtained by X-ray diffractometry (XRD) and optical spectrophotometry.

Journal ArticleDOI
TL;DR: The Langevin-equation based treatment of the nanotube charge carriers, assumed to be moving in the fluctuating field of ions in the flowing liquid, is shown to give a sublinear response, broadly in agreement with experiments.
Abstract: New experimental results, and a plausible theoretical understanding thereof, are presented for the flow-induced currents and voltages observed in single-walled carbon nanotube samples. In our experiments, the electrical response was found to be sublinear – nearly logarithmic – in the flow speed over a wide range, and its direction could be controlled by an electrochemical biasing of the nanotubes. These experimental findings are inconsistent with the conventional idea of a streaming potential as the efficient cause. Here we present Langevin-equation based treatment of the nanotube charge carriers, assumed to be moving in the fluctuating field of ions in the flowing liquid. The resulting Doppler-shifted force-force correlation, as seen by the charge carriers drifting in the nanotube, is shown to give a sublinear response, broadly in agreement with experiments