半导体量子器件物理讲座 第二讲 高电子迁移率晶体管（HEMT）

文章从异质界面的三角势阱中二维电子气的形成入手,计算了二维电子气的量子化能级及其面电子密度,对HEMT器件材料结构参数的优化、器件的电荷控制模型I－V特性作了分析。     

镜面起伏对1.55μm Si基MEMS光滤波器的影响

用传输矩阵方法,在简化的光学模型基础上,分别讨论了分布式Bragg反射镜DBR(Distributed Bragg Reflector)的生长精度及镜面起伏对1.55 μm Si基MEMS(Micro-Electro-Mechanical-System)可调谐光滤波器透射谱的影响.计算表明:DBR生长误差仅使主透射峰位置发生变化,而镜面起伏是导致主透射峰性能劣化的主要原因,它使得FWHM增大,透射峰强度下降.理论计算结果能较好地解释实验现像.在此基础上,进一步讨论了引起镜面起伏的多种原因,并提出了可能的解决方法.     

半导体量子器件物理讲座第三讲 异质结双极晶体管（HBT）

文章首先给出了同质结双极晶体管和异质结双极晶体管（HBT）在材料结构参数上的差异,这种差异表明,在器件的材料结构设计上已从掺杂设计步到了能带工程设计,和同质结双极晶体管相比,HBT具有更优越的性能,接着介绍了HBT的工作原理,典型的材料结构及器件的制作。     

High-Duty-Cycle Operation of GaAs/AlGaAs Quantum Cascade Laser above Liquid Nitrogen Temperature

We present a detailed study of λ- 9.75 μm GaAs/AlGaAs quantum cascade lasers. For a coated 2-rmm-long and 40-μm-wide laser, an optical power of 85 μ W is observed at 95% duty cycle at 80K. At a moderate driving pulse （1 kHz and 1% duty cycle）,the device presents a peak power more than 20mW even at 120K. At 80K, the fitted result of threshold current densities shows evidence of potential cw operation.     

A bistable, self-latching inverter by the monolithic integration of resonant tunnelling diode and high electron mobility transistor

This paper reports that the structures of AlGaAs/InGaAs high electron mobility transistor (HEMT) and AlAs/GaAs resonant tunnelling diode (RTD) are epitaxially grown by molecular beam epitaxy (MBE) in turn on a GaAs substrate. An Al_0.24Ga_0.76As chair barrier layer, which is grown adjacent to the top AlAs barrier, helps to reduce the valley current of RTD. The peak-to-valley current ratio of fabricated RTD is 4.8 and the transconductance for the 1-μm gate HEMT is 125mS/mm. A static inverter which consists of two RTDs and a HEMT is designed and fabricated. Unlike a conventional CMOS inverter, the novel inverter exhibits self-latching property.     

Nanoelectronic devices---resonant tunnelling diodes grown on InP substrates by molecular beam epitaxy with peak to valley current ratio of 17 at room temperature

This paper reports that InAs/In$_{0.53}$Ga$_{0.47}$As/AlAs resonant tunnelling diodes have been grown on InP substrates by molecular beam epitaxy. Peak to valley current ratio of these devices is 17 at 300K. A peak current density of 3kA/cm$^{2}$ has been obtained for diodes with AlAs barriers of ten monolayers, and an In$_{0.53}$Ga$_{0.47}$As well of eight monolayers with four monolayers of InAs insert layer. The effects of growth interruption for smoothing potential barrier interfaces have been investigated by high resolution transmission electron microscope.     

1.55μm MOEMS可调谐光滤波器调谐性能模拟

建立了等效单层梁模型和一维集总模型,用经典力学理论和传输矩阵方法模拟了多层材料构成且具有四臂固支梁结构的1.55 μm Si基MOEMS (Micro-Opto-Electro-Mechanical-Systems)可调谐滤波器的调谐特性.模拟调谐系数与实验结果吻合较好.     

1.55-μm Si-based MOEMS optical tunable filter

A prototype 1.55-μm Si-based micro-opto-electro-mechanical-systems (MOEMS) tunable filter is fabricated, employing surface micromachining technology. Full-width-at-half-maximum (FWHM) of the transmission spectrum is 23 nm. The tuning range is 30 nm under 50-V applied voltage. The device can be readily integrated with resonant cavity enhanced (RCE) detector and vertical cavity surface emitting laser (VCSEL) to fabricate tunable active devices.     

A Small Signal Equivalent Circuit Model for Resonant Tunnelling Diode

We report a resonant tunnelling diode （RTD） small signal equivalent circuit model consisting of quantum capacitance and quantum inductance. The model is verified through the actual InAs/In0.53Ga0.47As/AlAs RTD fabricated on an InP substrate. Model parameters are extracted by fitting the equivalent circuit model with ac measurement data in three different regions of RTD current-voltage （I-V） characteristics. The electron lifetime, representing the average time that the carriers remain in the quasibound states during the tunnelling process, is also calculated to be 2.09ps.     

半导体量子器件物理讲座

文章从异质界面的三角势阱中二维电子气的形成人手,计算了二维电子气的量子化能级及其面电子密度.对HEMT器件材料结构参数的优化、器件的电荷控制模型及I-V特性作了分析.