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Robert W. Keyes 《Contemporary Physics》2013,54(6):647-651
The spectacular success of the transistor in making a steady stream of increasingly powerful and affordable digital computers available through the 50 years since its invention is well known. Yet in spite of this remarkable record the same fifty years has witnessed a continuing series of proposals for replacing the transistor in computing systems with some other device. The tunnel diode and Josephson devices are notable examples. Some of these proposals have attracted many millions of pounds of industry and government support. Yet none has had any effect on computing technology. The problem of the many alternatives is that they do not use quantitative standard signals to represent digits; in other words, they are not truly digital. 相似文献
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A new bipolar transistor with a 20-period i-AlInAs/n+-InGaAs superlattice, prepared by metal organic chemical vapour deposition, has been fabricated and demonstrated. This superlattice is used as a confinement barrier for holes and a resonant tunneling (RT) route for electrons. Due to the RT effect within the 20-period superlattice near emitter–base p–n junction region, the N-shaped negative-differential-resistance (NDR) phenomena are observed under normal operation. A transistor action with a common-emitter current gain of 13 and a small offset voltage (90 mV) is achieved at room temperature. 相似文献
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Keeping in line with Moore's law requires increasing efforts in the development of alternative electronic devices. Multiple-gate transistors are very promising in order to suppress short-channel effects and to increase the current drive. Nevertheless, the fabrication of such devices represents a strong challenge for silicon process technology. One of the key steps of the process consists in shrouding the silicon fins in an isolating matrix, using a flowable oxide, namely hydrogen silsesquioxane (HSQ). The general objective of this work is to show that the properties of HSQ can be modified by appropriate thermal or plasma treatments to modulate its characteristics in terms of etching selectivity and surface topography. SEM characterization has shown that HSQ exhibits excellent planarization and gap fill capabilities, while AFM analysis, on 100 nm thick HSQ films deposited by spin on, reveals a roughness as low as 3 nm. Various oxygen plasma treatments have been applied to densify the HSQ films. Fourier transform infra-red spectroscopy (FT-IR) has shown very interesting qualitative and quantitative informations. Chemical and physical transformations from a Si-O-Si cage-like structure into an Si-O-Si network one have been observed. It is shown that exposure to oxygen plasma at high power (290 W) for a long time (20 min) or thermal curing at high temperature improves the resistance to wet etching using 1% hydrofluoric acid (HF). This densification technique holds the remarkable property to transform HSQ into an SiO2-like structure. 相似文献
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This Letter reports the novel use of poly(9‐vinylcarbazole) (PVK) as a dielectric interfacial layer for n‐type organic field‐effect transistors (n‐OFETs). With PVK, both the air stability and electron mobility of N,N′‐ditridecylperylene‐3,4,9,10‐tetracarboxylic diimide (PTCDI‐C13)‐based OFETs were improved. Among the PVKs with different weight‐average molecular weight (Mw), PVK with high Mw showed good performance. The high glass transition temperature of PVK enabled thermal post annealing of the active layer, which resulted in a high electron mobility of 0.61 cm2/Vs. This mobility was maintained at 90% and 59% after 4 days and 105 days in air, respectively. The PVK interfacial layer reduced the trapped charges in the PTCDI‐C13‐based n‐OFET for air‐exposure and caused a decrease in the threshold voltage shift.
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雪崩三极管因其快速性、高重复频率等特点被广泛应用于纳秒脉冲发生器。为了提高输出电压,常采用多管串联Marx电路。采用二极管代替传统多管串联Marx电路中的部分限流电阻以减少能量损耗,加快充电速度,提高重复频率,并分析了主电容和限流电阻对输出脉冲幅值和频率的影响。通过雪崩三极管的单管击穿实验,单个三极管的导通内阻最小约为2.5 Ω,多管串联Marx电路中的等效内阻使负载侧的输出电压降低,故采用多路Marx并联电路以提高输出电压幅值。通过改变Marx并联模块数量,研究了电路等效内阻对输出脉冲的影响;通过改变负载电阻值,验证了Marx并联电路在小负载下升压效果更佳。实验结果表明,通过相同的4路Marx并联电路进行放电实验,在50 Ω负载侧输出上升沿为3.4 ns、幅值为2.5 kV、可在15 kHz下稳定工作的脉冲。 相似文献
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为了实现氧化物薄膜晶体管(TFT)的低电阻布线,采用Cu作为氧化物TFT的源漏电极。通过优化成膜工艺制备了电阻率低至2.0μΩ·cm的Cu膜,分析了Cu膜的晶体结构、粘附性及其与a-IZO薄膜的界面,制备了以a-IZO为有源层和Cu膜的粘附层的TFT器件。结果表明:所制备的Cu膜呈多晶结构;引入a-IZO粘附层增强了Cu膜与衬底的粘附性;同时,Cu在a-IZO中的扩散得到了抑制。所制备的TFT的迁移率、亚阈值摆幅和阈值电压分别为12.9 cm2/(V·s)、0.28 V/dec和-0.6 V。 相似文献
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We conduct a theoretical study of the damage susceptibility trend of a typical bipolar transistor induced by a high-power microwave (HPM) as a function of frequency. The dependences of the burnout time and the damage power on the signal frequency are obtained. Studies of the internal damage process and the mechanism of the device are carried out from the variation analysis of the distribution of the electric field, current density, and temperature. The investigation shows that the burnout time linearly depends on the signal frequency. The current density and the electric field at the damage position decrease with increasing frequency. Meanwhile, the temperature elevation occurs in the area between the p-n junction and the n-n + interface due to the increase of the electric field. Adopting the data analysis software, the relationship between the damage power and frequency is obtained. Moreover, the thickness of the substrate has a significant effect on the burnout time. 相似文献
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We conduct a theoretical study of the damage susceptibility trend of a typical bipolar transistor induced by high-power microwave (HPM) as a function of frequency. The dependences of the burnout time and the damage power on the signal frequency are obtained. Studies of the internal damage process and the mechanism of the device are carried out from the variation analysis of the distribution of the electric field, current density, and temperature. The investigation shows that the burnout time linearly depends on the signal frequency. The current density and the electric field at the damage position decrease with increasing frequency. Meanwhile, the temperature elevation occurs in the area between the p-n junction and the n-n+ interface due to the increase of the electric field. Adopting the data analysis software, the relationship between the damage power and the frequency is obtained. Moreover, the thickness of the substrate has a significant effect on the burnout time. 相似文献
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Alexander N. Korotkov 《Superlattices and Microstructures》1996,20(4):581-585
The noise-limited charge sensitivity of a single-electron transistor with superconducting electrodes operating near the threshold of quasiparticle tunneling, can be considerably higher than thatof a similar transistor made of normal metals or semiconductors. The reason is that the superconducting energy gap, in contrast to the Coulomb blockade, is not smeared by the finite temperature. The same reason leads to the increase of the maximum operation temperaturedue to superconductivity. 相似文献
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提出一种超结硅锗碳异质结双极晶体管(SiGeC HBT)新结构.详细分析了新结构中SiGeC基区和超结结构的引入对器件性能的影响,并对其电流输运机制进行研究.基于SiGeC/Si异质结技术,新结构器件的高频特性优良;同时超结结构的存在,在集电区内部水平方向和垂直方向都建立了电场,二维方向上的电场分布相互作用大大提高了新结构器件的耐压能力.结果表明:超结SiGeC HBT与普通结构SiGeC HBT相比,击穿电压提高了48.8%;更重要的是SiGeC HBT器件中超结结构的引入,不会改变器件高电流增益、高频率特性的优点;新结构器件与相同结构参数的Si双极晶体管相比,电流增益提高了10.7倍,截止频率和最高震荡频率也得到了大幅度改善,很好地实现了高电流增益、高频率特性和高击穿电压三者之间的折中.对超结区域的柱区层数和宽度进行优化设计,随着柱区层数的增多,击穿电压显著增大,电流增益有所提高,截止频率和最高震荡频率减低,但幅度很小.综合考虑认为超结区域采用pnpn四层结构是合理的. 相似文献
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Silicon photodetectors and MOSFETs (Metal-Oxide-Semiconductor Field Effect Transistors) are frequently used devices for measuring ionizing radiation in health physics instrumentation. The Bipolar Junction Transistor (BJT) is not a typical device used as a detector for measuring some physical quantities in radiotherapy beams due to its loss of sensitivity to ionizing radiation, as a consequence of radiation damage in the silicon semiconductor substrate. Actually, the know-how of the BJT characteristic curves and its response to ionizing radiation leads us to suggest an alternative method to estimate the radiation dose value in breast cancer treatments. The BJT parameter to be evaluated before and after the irradiation procedure is the BJT amplification factor, also called DC gain β. In this work, the study was done using a BJT known as Darlington type, within an Alderson Rando anthropomorphic phantom. Darlington transistors have very high gain and this feature allowed that the BJT gain changes to be correlated with the dose of the radiation beam. The results indicate that this new method could be an alternative option to estimate the dose value in the phantom for measurements in breast cancer radiotherapy. 相似文献
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N.T. Bagraev L.E. Klyachkin A.M. Malyarenko W. Gehlhoff 《Superlattices and Microstructures》1998,23(6):1333-1338
We present high-temperature (77 K, 300 K) single-hole n+–p+–n transistors based on silicon diffusion nanostructures. This is made possible by utilizing a quantum wire with isolated quantum dots, which is naturally formed inside an ultrashallow p+-diffusion profile using nonequilibrium diffusion processes. 相似文献
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M. A. Glauberman V. V. Egorov N. A. Kanishcheva V. V. Kozel 《Russian Physics Journal》2009,52(1):66-75
The main physical mechanisms of operation of bipolar semiconductor transistor structures referred to as bipolar magnetosensitive
structures (BMS) are analyzed. It is demonstrated that vertical magnetosensitive structures must be excluded from the BMS
class, whereas horizontal structures form one class from the viewpoint of model representations irrespective of the direction
of their magnetic axis. The mechanisms of BMS sensitivity in which the determining parameter is the mobility of carriers admit
a common model representation and hence can be considered as a common redistribution mechanism. The BMS magnetic sensitivity,
when estimating its conversion efficiency, is sufficiently correctly described by the one-dimensional continuity equation
irrespective of the concrete boundary conditions.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 58–66, January, 2009. 相似文献
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文章介绍了肖克莱的生平事迹及其在物理学上取得的成就,着重论述了他提出的晶体管理论以及据此发明的晶体管对后世的影响,指出肖克莱提出的晶体管理论奠定了今天半导体科学技术发展的基础。 相似文献
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Guang-Cai Yuan Zheng Xu Su-Ling Zhao Fu-Jun Zhang Xiao-Yun Jia Na Xu Xu-Rong Xu 《Applied Surface Science》2009,255(11):5995-5998
To investigate the effect of composition of SiNx on the properties of organic thin-film transistors (OTFTs), we fabricated bottom gate top contact OTFTs devices with different composition SiNx gate insulator. Pentacene based OTFTs with SiNx insulator, prepared using an interface modification process of UV-ozone treatment, exhibited effective mobility of 0.63 cm2/Vs and on/off current ratio of 105. Overall improvement in field-effect mobility, threshold voltage was observed as silicon content in SiNx increases. The results demonstrate that the viability of using SiNx for OTFTs and of UV-ozone treatment could be used to improve the properties of organic thin-film transistors. The dependence of the contact angle on the SiNx film composition is evident for the untreated samples, the contact angle increases as the silicon content in the untreated nitride film increases. In contrast, the rise in contact angle across all samples after surface treatment signifies effective surface modification to promote hydrophobicity of the nitride surface. The hydrophobic surface is needed for the organic semiconductor. 相似文献