共查询到20条相似文献,搜索用时 15 毫秒
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Chen K.J. Hong W.K. Lin C.P. Chen K.H. Chen L.C. Cheng H.C. 《Electron Device Letters, IEEE》2001,22(11):516-518
A low turn-on voltage, field emission triode array has been fabricated using the selective deposition of carbon nanotubes (CNTs) in a microwave plasma chemical vapor deposition (MPCVD) system. The field emission triodes exhibited a low turn-on voltage of 13 V and a large emission current of 23 μA with the gate voltage at 60 V. Short-term stress reveals a 10% current fluctuation within 1800 sec. The excellent electric properties suggest that the array shows potential for application in field emission displays and vacuum microelectronics 相似文献
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Yasin Kanbur Mihai Irimia-Vladu Eric D. Głowacki Gundula Voss Melanie Baumgartner Günther Schwabegger Lucia Leonat Mujeeb Ullah Hizir Sarica Sule Erten-Ela Reinhard Schwödiauer Helmut Sitter Zuhal Küçükyavuz Siegfried Bauer Niyazi Serdar Sariciftci 《Organic Electronics》2012,13(5):919-924
We report on the fabrication and performance of vacuum-processed organic field effect transistors utilizing evaporated low-density polyethylene (LD-PE) as a dielectric layer. With C60 as the organic semiconductor, we demonstrate low operating voltage transistors with field effect mobilities in excess of 4 cm2/Vs. Devices with pentacene showed a mobility of 0.16 cm2/Vs. Devices using tyrian Purple as semiconductor show low-voltage ambipolar operation with equal electron and hole mobilities of ~0.3 cm2/Vs. These devices demonstrate low hysteresis and operational stability over at least several months. Grazing-angle infrared spectroscopy of evaporated thin films shows that the structure of the polyethylene is similar to solution-cast films. We report also on the morphological and dielectric properties of these films. Our experiments demonstrate that polyethylene is a stable dielectric supporting both hole and electron channels. 相似文献
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利用脉冲电化学沉积技术,以NiSO4·6H2O为电镀液在镀Cr硅基片上沉积低密度、直径在150nm左右的Ni催化剂颗粒,在此基础上,采用乙炔、氨气作为气源,采用等离子体增强化学气相沉积(PECVD)技术制备分散定向的碳纳米管阵列。研究了等离子体预处理技术对纳米管制备的影响以及该阵列的场发射性能,证明低密度的碳纳米管阵列阴极能有效地降低场屏蔽效应,进而提高场发射性能,其场发射的开启电场强度约为2.39V/μm。 相似文献
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Turn-on voltage of about 30 V is observed in 1-μm gate-aperture Si field emitter arrays fabricated using oxidation sharpening and chemical mechanical polishing. Small emitter tip radius (~10 nm) was achieved from low temperature oxidation sharpening. The gate leakage current is observed to be less than 0.01% of emitter current over the range of measurement. Devices show excellent emission uniformity for different sized arrays. Current saturation was observed at high gate voltages because of low dopant concentration of the substrate. Below the saturation region, the current-voltage characteristics obey the Fowler-Nordheim field emission theory 相似文献
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Kawahara T. Saeki S. Jyouno Y. Miyamoto N. Kobayashi T. Kimura K. 《Solid-State Circuits, IEEE Journal of》1998,33(1):126-132
A fabricated bandgap generator using 0.25-μm Flash memory process generated a stable reference voltage under 4 V, boosted from an external power supply of 2.5 V. The generated voltage was 1.297±0.025 V at a power supply of 4 V±10%; the temperature dependence was +0.7 mV/°C. The characteristics of a triple-well bipolar transistor for the Flash memory process are sufficient for a reference voltage generator; fT is 230 MHz, and HFE is 70. Dynamic operation reduced the average current consumption from 306 to 8.6 μA. Fabricated voltage-doubler circuits generated a voltage 1.8 times larger than that from conventional charge-pump circuits 相似文献
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A very high conversion gain mixer of frequency 350 MHz is designed using the injection-locked technique. The mixer is based on a common-base Clapp oscillator which is free-running at a frequency of 350 MHz. Using the injection-locked technique, the nonlinear resistance of the oscillator is modulated by the injection source which provides negative resistance amplification to the RF signal. It gives conversion gain as high as 30 dB with good noise performance 相似文献
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提出了一种新的两级环形振荡器结构,通过控制PMOS的衬底电压,来降低PMOS管的阈值电压,从而使新的环形振荡器可以在低电压下工作到很高的频率。仿真结果表明,在电源电压为1V,调节电压在0~1V范围内变化时,振荡器的频率为300MHz-4GHz。 相似文献
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Consoli A. Gennaro F. Testa A. Consentino G. Frisina F. Letor R. Magri A. 《Power Electronics, IEEE Transactions on》2000,15(3):575-581
This paper analyzes an anomalous failure mechanism detected on last generation low voltage power metal oxide semiconductor (MOS) devices at low drain current. Such a behavior, apparently due to a kind of second breakdown phenomenon, has been scarcely considered in literature, as well as in manufacturer data sheets, although extensive experimental tests show that it is a common feature of modern low voltage metal oxide semiconductor held effect transistor (MOSFET) devices. The paper starts by analyzing some failures, systematically observed on low voltage power MOSFET devices, inside the theoretical forward biased safe operating area. Such failures are then related to an unexpected thermal instability of the considered devices. Experimental tests have shown that in the considered devices the temperature coefficient is positive for a very wide drain current range, also including the maximum value. Such a feature causes hot spot phenomena in the devices, as confirmed by microscope inspection of the failed devices. Finally, it is theoretically demonstrated that the thermal instability is a side effect of the progressive die size and process scaling down. As a result, latest power MOSFETs, albeit more efficient and compact, are less robust than older devices at low drain currents, thus requiring specific circuit design techniques 相似文献
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Simulation of field emission microtriodes 总被引:1,自引:0,他引:1
Vacuum microtriode RF amplifier performance, based upon a unit cell with a conical field emitter tip, gate, and anode, was evaluated using computer simulation. Electron emission was calculated from the Fowler-Nordheim equation. The dependence of emitted current, transconductance, and field enhancement upon geometrical factors, e.g., tip sharpness, tip height, cone half-angle, and gate hole radius, is shown. The device design parameters of transconductance, cutoff frequency, small signal gain, and efficiency have been calculated. Electron streamlines and current flux are shown for time-dependent RF input. Because a compact electron beam source has wide application, the normalized beam emittance, brightness, and beam quality are calculated for a typical case. Potential difficulties with anode power deposition are noted 相似文献
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A low supply voltage high PSRR voltage reference in CMOS process 总被引:7,自引:0,他引:7
This paper describes a bandgap voltage reference circuit that operates with a 3 V power supply and is compatible with a digital CMOS process. The use of a simple circuit topology results in a small silicon area of 0.07 mm2, a power consumption of 1 mW and a high power supply rejection over a wide frequency band. The circuit realizes a temperature coefficient of 85 ppm/°C and a standard deviation of 20 mV without trimming 相似文献
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An on-chip high voltage tolerant 4VDD charge pump with symmetrical architecture in a standard low voltage 1.8 V 0.18 /spl mu/m CMOS process is presented. For a 250 k/spl Omega/ load, circuit efficiency of the charge pump is approximately 71%. All the MOS transistors satisfy typical voltage stress related reliability requirements for standard low voltage CMOS devices. 相似文献
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This paper presents an up-conversion mixer for 2.4-2.4835 GHz wireless sensor networks (WSN) in 0.18 μm RF CMOS technology. It was based on a double-balanced Gilbert cell type, with two Gilbert cells having quadrature modulation applied. Current-reuse and cross positive feedback techniques were applied in the mixer to boost conversion gain; the current source stage was removed from the mixer to improve linearity. Measured results exhibited that under a 1 V power supply, the conversion gain was 5 dB, the input referred 1 dB compression point was -11 dBm and the IIP3 was -0.75 dBm, while it only consumed 1.4 mW. 相似文献
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This paper describes and analyses the impact of the Ti layer, which is embedded between the insulator and top electrode, on the programming characteristic of the Al-HfO2-Al antifuse. The programming voltage of the antifuse with 120 Å HfO2 is properly reduced from 5.5 to 4.6 V with an embedded Ti layer. Low on-state resistance (~19 Ω) and low programming voltage (4.6 V) is demonstrated in the embedded Ti antifuse with 120 Å HfO2 while keeping sufficient off-state reliability. The antifuse embedded with a Ti layer between the insulator and top electrode has been developed and has potential in field programmable devices. 相似文献
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In this work, we present a method to increase the performance in solution processed organic field effect transistors (OFET) by using gel as dielectric and molecular doping to the active organic semiconductor. In order to compare the performance improvement, Poly (methylmethacrylate) (PMMA) and Poly (3-hexylthiophene-2,5-diyl) P3HT material system were used as a reference. Propylene carbonate (PC) is introduced into PMMA to form the gel for using as gate dielectric. The mobility increases from 5.72×10−3 to 0.26 cm2 V s–1 and operation voltage decreases from −60 to −0.8 with gel dielectric. Then, the molecular dopant 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ) is introduced into P3HT via co-solution. The mobility increases up to 1.1 cm2 V s–1 and the threshold voltage downs to −0.09 V with doping. The increase in performance is discussed in terms of better charge inducing by high dielectric properties of gel and trap filling due to the increased carrier density in active semiconductor by molecular doping. 相似文献
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Geis M.W. Twichell J.C. Efrernow N.N. Krohn K.E. Stern M.B. Lyszczarz T.M. 《Electron Device Letters, IEEE》1997,18(12):595-598
This letter describes the fabrication and operation of diamond grit gated cathodes. The structure is similar to Spindt-type cathode, but the field emission cone is replaced with a more planar diamond grit layer 50 to 200 nm thick. Although the minimum lithographic dimension of these cathodes is from 1 to 5 μm, these devices have exceptionally low turn-on voltages, 5 to 7 V. Cathode current noise is less than 2.5% rms with a maximum absolute current variation of 6.7% over a 6 h period. These devices can operate in pressures of nitrogen above 133 Pa (1 Torr). Although operation in 6.6×10-2 Pa (5×10 -4 Torr) with more reactive gasses, O2 or H2 S, degrades performance, the cathodes recover when the pressure is reduced to ⩽1.3×10-4 Pa (1×10-6 Torr). Gate current varies from 0.2 to 100 times the emitted current and depends on the technique used to deposit the diamond grit. High current densities (>10 A cm-2), low gate voltages (<50 V), low emission noise, excellent longevity, temporal uniformity, and ease of fabrication make these devices potential cathodes for flat panel displays. However, excessive gate current and unsatisfactory processing reproducibility at present limit their general application 相似文献