基于共振光隧穿效应的角加速度传感器设计

阐述了一种基于共振光隧穿效应的角加速度传感器的设计方法,分析了其传感特性,并以共振光隧穿理论为基础,利用Mathematica软件进行了仿真分析。该加速度传感器的品质因数可以达到1.96×10⁸,远高于经典F-P腔的品质因数8.183×104。灵敏度可以达到0.1°/nm,     

平面型共振隧穿二极管的制作

采用离子注入方法制作了一种新型平面共振隧穿二极管（RTD）,通过离子注入将器件之间进行隔离,避免了传统台面型RTD中采用的台面刻蚀所带来的一些缺点,并且表现出良好的I-V特性,峰谷电流比为3．4．通过该方法制作的RTD将更有利于RTD的平面集成．     

极化效应对AlN/GaN共振隧穿二极管电流特性的影响

本文采用半经验紧束缚能带理论,通过自洽计算薛定谔方程和泊松方程研究了AlN/GaN共振隧穿二极管中极化效应对电流的影响.结果发现,极化效应导致电流曲线发生不对称性,并影响电流的共振电压位置,这与实验报道的结果相一致.并且随着极化电荷的增加,在一定的偏压条件下,只能观测到一个子能级隧穿或者根本没有负微分电阻现象发生.     

肖特基栅型共振隧穿三极管器件模型的研究

基于共振隧穿二极管(RTD)的电流-电压方程,结合对肖特基栅型共振隧穿三极管(SGRTT)物理机制的分析和计算,推导出了SGRTT器件的器件模型。根据实际器件的材料结构、版图参数等指标计算得到的SGRTT器件模型,能很好地与实际器件的特性相吻合。利用PSPICE软件,该模型可准确快捷地实现电路功能验证和仿真,此项研究的结果为共振隧穿器件的电路集成和研制奠定了基础。     

基于AlAs/InGaAs/GaAs共振隧穿效应的纳机电声传感器研制

本工作设计了一种基于AlAs/InGaAs/GaAs量子隧穿效应的纳机电拍子式声传感器,并采用ANSYS有限元分析软件对敏感元件的布置位置进行了最优化仿真设计.在加工工艺上,采用双空气桥技术和Au/Ge/Ni合金膜系欧姆接触技术有效降低了电容、电阻等对器件结构性能的影响;在传感器的具体加工过程中,共振隧穿结构(RTS)和拍子结构是通过控制孔技术一次流片完成的.对所加工的传感器进行了初步测试,结果表明,传感器频响能较好的与仿真结果相吻合,1.3KHz时同时具有较好的线性特性.     

隧穿型量子效应薄膜材料制备技术

探讨了隧穿型量子效应薄膜材料制备技术,并应用分子束外延方法制备了典型结构外延材料GaAs基共振隧穿二极管,经过器件验证,得到了较好的结果.重点讨论了关键制备技术,包括束流精细控制和间歇式生长方式,主要是为了生长出更接近完美的晶体结构和晶体表面,并分析了测试结果和器件验证结果,最终得出整套隧穿型量子效应薄膜材料制备技术.     

极化效应对AIN／GaN共振隧穿二极管电流特性的影响

本文采用半经验紧束缚能带理论，通过自洽计算薛定谔方程和泊松方程研究了A1N／GaN共振隧穿二极管中极化效应对电流的影响。结果发现，极化效应导致电流曲线发生不对称性，并影响电流的共振电压位置，这与实验报道的结果相一致。并且随着极化电荷的增加，在一定的偏压条件下，只能观测到一个子能级隧穿或者根本没有负微分电阻现象发生。     

磁性隧道结中自旋相关的隧穿输运

全面回顾和总结了磁性隧道结中自旋相关的隧穿这一研究领域的理论和实验方面的最新研究进展。讨论了影响磁性隧道结的自旋极化和隧穿磁电阻的各种因素及反映铁磁层和铁磁／绝缘层界面电子结构在隧穿中重要作用的理论模型和近期实验，同时也讨论了绝缘势垒和铁磁／绝缘层界面中的无序性在隧穿过程中对自旋极化与磁电阻效应的影响。     

单折梁结构的水平式隧穿磁强计的仿真

水平式隧穿磁强计梁的结构设计可采用直梁和折叠梁.直梁结构质量弹簧系统的弹性系数可通过几何建模的方法确定,但折叠梁结构则难于采用该方法确定.本文以单折梁为例,采用有限元仿真,通过建立单折梁结构和直梁结构在受到相同外力时位移变化之间的关系,推导出单折梁结构的弹性系数和驱动电压计算公式.此外,通过分析单折梁结构和直梁结构的水平式隧穿磁强计1～4阶模态振型,发现单折梁结构的1～3阶模态的运动方向与直梁结构相同;单折梁结构第4阶模态的方向既有绕x轴的转动,也有绕Z轴的转动,绕z轴的转动为主要运动.     

自对准栅型谐振隧穿晶体管试制

针对谐振隧穿二极管(RTD)在通用电路应用中的局限性,提出并设计了自对准栅型谐振隧穿晶体管结构,进行了材料的分子束外延,采用传统湿法腐蚀、金属剥离、台面隔离和空气桥互连工艺,初步研制出具有较明显栅控能力的谐振隧穿晶体管(RTT)单管,其峰值电流密度高达80.8 kA/cm2,峰谷电流比为3.6,负阻阻值在20Ω左右.研究还发现,器件的峰值电流随栅压增大而减小,谷值电流随栅压增大而增大,而且出现零点分离.这些现象与栅的纵向位置控制不当有关,可以通过减小栅间发射极宽度,缩短栅与势垒层距离,和减小发射层掺杂浓度得到改善.     

Characterizing nonlinear resonant structures

A method for the characterization of nonlinear resonant systems is proposed, which is based on the measurement of the transfer coefficient as a function of the frequency at constant amplitude of oscillations in the resonator. In this case, the amplitude-dependent characteristics of the nonlinear resonator, such as the level of losses and the resonance frequency, are the same for all points of the measured resonance curve. This situation can be realized by carrying out the measurements at a fixed output power. The resonance curve measured using this approach, in contrast to the standard amplitude-frequency characteristic obtained at a constant input power, has a Lorentz shape even for a strongly nonlinear system (irrespective of the operative mechanism of nonlinearity), which allows the Q value to be correctly defined (so that it will be constant for the entire measured resonance curve) and determined. The proposed method is illustrated by measuring the characteristics of a superconducting filter in a nonlinear regime.     

Template synthesized Cu-Se microstructures as resonant tunneling diodes

We report on resonant electron tunneling through Cu-Se microstructure fabricated by direct current electro-deposition in templates formed by etching the tracks of heavy ions in polymer (polycarbonate) foils. Negative differential resistance has been observed in the I-V curves of the so fabricated array of Cu-Se microstructures. Results show that electrochemical deposition in the pores of nuclear track filters can be very effective way of fabricating resonant tunneling diodes. SEM results show that the diameter of these aligned microstructures are consistent with the diameter of the templates used.     

Noise-tolerant quantum MOS circuits using resonant tunneling devices

Resonant tunneling devices are promising candidates for comingling with traditional CMOS circuits, yielding better performance in terms of reduced silicon area, faster circuit speeds, lower power consumption, and improved circuit noise margin. These resonant tunneling devices have several intrinsic merits that include: high current density, low intrinsic capacitance, the negative differential resistance effect, and relative ease of fabrication. In this paper, we briefly describe some circuit configurations of Silicon quantum MOS logic family, with a special emphasis on noise-tolerant design that is now becoming an important constraint for robust and reliable operation of very deep submicron VLSI chips. More specifically, we discuss a novel strategy to incorporate quantum-tunneling devices into mainstream dynamic CMOS circuits with a view to improving the noise immunity of the latter. Dynamic CMOS circuits are rampantly used in modern high-performance VLSI chips achieving the best tradeoff between circuit speed, silicon area, and power consumption. However, they are inherently less noise-tolerant than their static CMOS counterparts. With the continuously deteriorating noise margins due to aggressive down scaling of the CMOS fabrication technologies, the performance overhead due to existing remedial noise-tolerant circuit techniques becomes prohibitively high. In this paper, we propose a novel method that utilizes the negative differential resistance property of quantum tunneling devices. The performance and noise immunity of the proposed circuits are evaluated through both analytical studies and SPICE simulations. We demonstrate that the noise tolerance of dynamic CMOS circuits can be greatly improved with very little degradation in circuit speed. The benefit of the proposed technique is evident even for currently available Silicon-based resonant tunneling devices with a relatively small peak-to-valley current ratio.     

New type of oscillations in bistable resonant tunneling diodes

It is shown that that the coupling of resonant tunneling diodes with an external electrical circuit containing an oscillatory loop can lead to the excitation of spatiotemporal oscillations. Pis’ma Zh. Tekh. Fiz. 25, 64–68 (May 26, 1999)     

Magnetic field enhanced resonant tunneling in a silicon nanowire single-electron-transistor

We report fabrication, measurement and simulation of silicon single-electron-transistors made on silicon-on-insulator wafers. At T-2 K, these devices showed clear Coulomb blockade structures. An external perpendicular magnetic field was found to enhance the resonant tunneling peak and was used to predict the presence of two laterally coupled quantum dots in the narrow constriction between the source-drain electrodes. The proposed model and measured experimental data were consistently explained using numerical simulations.     

The effect of the resonant mode structure on flux tunneling in SQUIDs

The problem of macroscopic quantum tunneling in SQUIDs is discussed, taking into account the resonant mode structure of typical devices. These are evaluated for the particular case of a SQUID formed from a conical point intersecting a hemispherical cavity, and it is shown that the conventional representation of a SQUID as a Josephson junction in parallel with an inductor and a capacitor is a good first approximation in most cases, provided the inductance and capacitance used are those of the whole device rather than of the weak link alone. The discussion is extended to another case of practical importance, where such a cavity is connected to an outer hole by a flange, and it is found that if the capacitance of the flange is large, the tunneling behavior is largely independent of the presence of the outer hole, apart from the effects of any dc bias.