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建立了SACM型In0.53Ga0.47As/In0.52Al0.48As雪崩光电二极管(APD)的分析模型,通过数值研究和理论分析设计出高性能的In0.53Ga0.47As/In0.52Al0.48As APD。器件设计中,一方面添加了In0.52Al0.48As势垒层来阻挡接触层的少数载流子的扩散,进而减小暗电流的产生;另一方面,雪崩倍增区采用双层掺杂结构设计,优化了器件倍增区的电场梯度分布。最后,利用ATLAS软件较系统地研究并分析了雪崩倍增层、电荷层以及吸收层的掺杂水平和厚度对器件电场分布、击穿电压、IV特性和直流增益的影响。优化后APD的单位增益可以达到0.9 A/W,在工作电压(0.9 Vb)下增益为23.4,工作暗电流也仅是纳安级别(@0.9 Vb)。由于In0.52Al0.48As材料的电子与空穴的碰撞离化率比InP材料的差异更大,因此器件的噪声因子也较低。 相似文献
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利用分子束外延 (MBE)技术在高指数面 Ga As衬底上自组织生长了应变 In Ga As/Ga As量子线材料。原子力显微镜 (AFM)观测结果表明量子线的密度高达 4× 1 0 5/cm。低温偏振光致发光谱 (PPL)研究发现其发光峰半高宽 (FWHM)最小为 9.2 me V,最大偏振度可达 0 .2 2。以 Al Ga As为垫垒 ,In Ga As/Ga As量子线为沟道 ,成功制备了量子线场效应管 (QWR-FET)结构材料 ,并试制了器件 ,获得了较好的器件结果 相似文献
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采用普通接触曝光研制成栅长为0 .2 5 μm的Ga As基In Al As/ In Ga As变组分高电子迁移率晶体管(MHEMT) ,测得其跨导为5 2 2 m S/ m m,沟道电流密度达4 90 m A/ mm,截止频率为75 GHz,比同样工艺条件下Ga As基In Ga P/ In Ga As PHEMT的性能有很大的提高.对该器件工艺及结果进行了分析,提取了器件的交流小信号等效电路模型参数,并提出了进一步得到高稳定性、高性能器件的方法. 相似文献
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应用电子束直写技术成功制作了栅长100nm的高性能In0.52Al0.48As/In0.53Ga0.47As GaAs MHEMT(渐变组分高电子迁移率晶体管)。从工艺角度,结合器件的小信号等效电路的理论分析,优化了器件T形栅尺寸与工艺,从而减小了器件寄生参数,达到了较好的器件性能。最终制作的In0.52Al0.48As/In0.53Ga0.47As MHEMT饱和电流达到460mA/mm,夹断电压-0.8V,在Vgs为-0.23V时的最大非本征跨导gm为940mS/mm,截止频率ft达到220GHz,最大振荡频率fmax大于200GHz。 相似文献
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报道了用 MBE技术生长的 Ga As基 In Al As/In Ga As改变结构高电子迁移率晶体管 (MHEMT)的制作过程和器件的直流性能。对于栅长为 0 .8μm的器件 ,最大非本征跨导和饱和电流密度分别为 3 5 0 m S/mm和1 90 m A/mm。源漏击穿电压和栅反向击穿电压分别为 4V和 7.5 V。这些直流特性超过了相同的材料和工艺条件下 Ga As基 PHEMT的水平 ,与 In P基 In Al As/In Ga As HEMT的性能相当 相似文献
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《红外与毫米波学报》2021,40(2)
用分子束外延系统(MBE)生长高质量Ga Sb基AlInAsSb四元数字合金制作雪崩光电二极管(APD)。为了克服随机体材料生长方式发生的偏析现象,采用迁移增强的数字合金生长方式,其快门顺序为Al Sb,Al As,Al Sb,Sb,In,In As,In,Sb。其高分辨率X射线衍射(HRXRD)曲线显示出尖锐的卫星峰,并显示出几乎完美的晶格匹配,其原子力显微镜(AFM)图像上也可以观察到光滑的表面形貌。使用优化的数字合金生长方式,制备了分离吸收、渐变、电荷和倍增(SAGCM)型的AlInAsSb数字合金APD。在室温下,器件在95%击穿时,暗电流密度为0.95 m A/cm2,击穿前最大稳定增益高达~100,其器件的高性能显示出光电领域进一步发展的潜力。 相似文献
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A continuous-time (CT) sigma-delta modulator (SDM) for condenser microphone readout interfaces is presented in this paper. The CT SDM can accommodate a single-ended input and has high input impedance, so that it can be directly driven by a single-ended condenser microphone. A current-sensing boosted OTA-C integrator with capacitive feedforward compensation is employed in the CT SDM to achieve high input impedance and high linearity with low power consumption. Fabricated in a \(0.35\) - \(\upmu\) m complementary metal-oxide-semiconductor (CMOS) process, a circuit prototype of the CT SDM achieves a peak signal-to-noise-and-distortion ratio of 74.2 dB, with 10-kHz bandwidth and \(801\) - \(\upmu\) W power consumption. 相似文献
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Yi-Jen Chiu Hsu-Feng Chou Kaman V. Abraham P. Bowers J.E. 《Photonics Technology Letters, IEEE》2002,14(6):792-794
An InGaAsP multiquantum-well traveling-wave electroabsorption modulator is demonstrated with high extinction ratio and modulation efficiency. By designing a strain-compensated quantum-well active region with traveling-wave design, high saturation power (>14 dBm) for >20-GHz high-speed performance (1.5 dB drop at 20 GHz) is achieved. Due to high modulation efficiency (>30 dBN for 0 to 1 V 40-dB extinction ratio in 2 V), error free 10-Gb/s operation with 1 Vp-p driving voltage is obtained. By comparing codirections and counterdirections of optical and microwave interactions, pulse generation at 40 GHz shows that the traveling-wave performance has an advantage for short pulses with high-power output, where pulsewidth as short as 4.5 ps is obtained in this kind of device 相似文献
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Mohammad Elmi Mahdi Tavassoli Ali Jalali 《Analog Integrated Circuits and Signal Processing》2018,94(3):451-467
Harmonic selectivity and inaccessibility to accurate low-power high frequency clock generator are two main imperfections in the tunable N-path filters. In this paper, conventional N-path filter and conventional harmonic rejection (HR) N-path architectures are analyzed, and related equations are derived and are verified by simulation results. Furthermore, a wideband tunable receiver front-end using HR N-path switching systems is proposed. Using third harmonic of filter response instead of fundamental harmonic, the required input clock frequency in the multi-phase clock generator is decreased by a factor of three. The receiver front-end benefits low and high frequency bands. At low frequency band (0.4–1.2 GHz) the first harmonic, and at high frequency band (1.2–3.3 GHz) the third harmonic of filter response are selected and are downconverted to the baseband frequency. The structure is designed and is simulated using CMOS-90 nm technology in schematic level. The total power consumption and \(S_{11}\) are \(<27.14\) mW and \(-13.5\) dB, respectively. Furthermore, NF at low and high frequency bands are 2.56 and 3.53 dB, respectively. 相似文献
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In this study, solution-processable carbazole-type host materials, 1,3-bis(3-(3,6-di-n-butylcarbazol-9-yl)phenyl)benzene (BCzPPh) and 4,6-bis(3-(3,6-di-n-butylcarbazol-9-yl)phenyl)pyrimidine (BCzPPm), were synthesized for use in phosphorescent organic light-emitting devices (OLEDs). Both host materials possess a high solubility in common organic solvents and high triplet energy to confine excitons to the phosphorescent emitter. The two nitrogen atoms in the central pyrimidine ring of BCzPPm have a profound effect on the photoluminescence properties and the electron-accepting capability. When doped with the green phosphorescent emitter tris(2-(4-tolyl)phenylpyridine)iridium (III), BCzPPh exhibited power efficiencies and external quantum efficiencies above 30 lm/W and 13%, respectively, in a simple bilayer OLED. 相似文献
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We simulate etching trenches in Si with a high (over 15) aspect ratio, i.e., the ratio between the trench depth and width in Cl2 plasma in wide ranges of the ratio between the flows of Cl atoms and Cl+ ions (3–300) and ion energies (50–250 eV). We demonstrate that the trenches with a high aspect (HA) ratio (~20) and almost vertical walls can be formed at the maximum energies of E i = 250 eV and R = 300. At the lower values of these parameters, etching an HA-ratio trench is accompanied by its narrowing, curvature, or bending. We discuss the origin of the HA-trench bending effect at small R values and a high energy of the incident ions. 相似文献
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Strongly Dipolar Polythiourea and Polyurea Dielectrics with High Electrical Breakdown,Low Loss,and High Electrical Energy Density 总被引:1,自引:0,他引:1
Shan Wu Quinn Burlingame Zhao-Xi Cheng Minren Lin Q. M. Zhang 《Journal of Electronic Materials》2014,43(12):4548-4551
Dielectric materials with high electric energy density and low loss are of great importance for applications in modern electronics and electrical systems. Strongly dipolar materials have the potential to reach relatively higher dielectric constants than the widely used non-polar or weakly dipolar polymers, as well as a much lower loss than that of nonlinear high K polymer dielectrics or polymer–ceramic composites. To realize the high energy density while maintaining the low dielectric loss, aromatic polythioureas and polyureas with high dipole moments, high dipole densities, tunable molecular structures and dielectric properties were investigated. High energy density (>24 J/cm3), high breakdown strength (>800 MV/m), and high charge–discharge efficiency (>90%) can be achieved in the new polymers. The molecular structure and film surface morphology were also studied; it is of great importance to optimize the fabrication process to make high-quality thin films. 相似文献
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Dang-Kièn Germain Pham Patricia Desgreys Patrick Loumeau Tim Ridgers Guillaume Monnerie 《Analog Integrated Circuits and Signal Processing》2013,77(2):235-245
This article presents the high-level design of general multi-stage noise band cancellation (MSNBC) $\Upsigma\Updelta$ analog-to-digital converters (ADC). The MSNBC architecture enables to extend the conversion bandwidth of a primary modulator and to provide high resolution conversion. Moreover, this architecture should offer a low power consumption. This type of ADC is very useful for wideband and high resolution application such as the digitization of data for the linearization of base station (BTS) power amplifiers. This article introduces the MSNBC architecture and provides a methodology for the high-level design of such ADC for both discrete-time and continuous-time implementation. The methodology enables the design of stable and high resolution modulators and, the direct synthesis of digital FIR filters that are used for noise cancellation. This methodology is fast and useful to design high performance MSNBC $\Upsigma\Updelta$ ADC. 相似文献
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Based on the vector diffraction theory, a super-resolution longitudinally polarized optical needle with ultra-long depth of focus (DOF) is generated by tightly focusing a radially polarized beam that is modulated by a self-designed ternary hybrid (phase/amplitude) filter (THF). Both the phase and the amplitude patterns of THF are judiciously optimized by the versatile particle swarm optimization (PSO) searching algorithm. For the focusing configuration with a combination of a high numerical aperture (NA) and the optimized sine-shaped THFs, an optical needle with the full width at half maximum (FWHM) of 0.414λ and the DOF of 7.58λ is accessed, which corresponds to an aspect ratio of 18.3. The demonstrated longitudinally polarized super-resolution light needle with high aspect ratio opens up broad applications in high-density optical data storage, nano-photolithography, super-resolution imaging and high-efficiency particle trapping. This work has been supported by the National Natural Science Foundation of China (Nos.61575139, 61605136, 51602213 and 11604236), and the Youth Foundation of the Taiyuan University of Technology (No.2015QN066). This paper was recommended by the 9th International Conference on Information Optics and Photonics (CIOP 2017). E-mail:niezhongquan@tyut.edu.cn 相似文献