宽禁带半导体SiC的离子束合成,掺杂隔离与智能剥离

碳化硅作为新一代宽禁带半导体材料，在高温、高频、高功率、抗辐照电子器件中有着十分广阔的潜在应用前景．文章结合作者的工作，综述了离子束技术在ＳｉＣ研究中的应用，其中包括ＳｉＣ的合成、掺杂、器件隔离和智能剥离．     

一种新型光电材料—β—FeSi2的结构,光电特性及其制备

β－ＦｅＳｉ２是近年来发展起来的新型硅基光电材料，详细介绍了β－ＦｅＳｉ２的结构，电学、光学性质以及它的制备技术。对目前存在的问题以及未来的研究动向作了简要的讨论。     

A Stable Porous Silicon Dielectric Reflector with a Photonic Band Gap Centred at 10μm

By pulsed anodic etching at low temperature, we prepared a porous silicon reflector with a photonic band gap centred in the long-wavelength infrared spectral region （centred at about 12 μm）. After proper oxidation process, the stable reflector structure, which can reflect electromagnetic wave from 8 μm to 12 μm （centred at 10 μm） within wide incidence angles （about 50°）, is obtained. The wavelength shift of absorption peak of Si-H and Si-O shows the influence of oxidation process and indicates the stability of oxidized porous silicon dielectric reflector, which offers possible applications for the room temperature infrared sensor.     

一维多孔硅声子晶体的带隙研究

多孔硅的力学性质随多孔度有较大变化,因此可以用多孔硅材料来构建声子晶体结构.本文将在理论上讨论一维多孔硅声子晶体的带隙,设计出宽禁带声子晶体结构,分析其相关的物理特性.计算结果表明薄的高孔度插入层将获得宽的带隙,而声子晶体异质结能够获得更宽带隙.     

An Array of One-Dimensional Porous Silicon Photonic Crystal Reflector Islands for a Far-Infrared Image Detector

With the aid of photolithography, an array of one-dimensional porous silicon photonic crystai reflector islands for a far infrared image detector ranging from 10 μm to 14 μm is successfully fabricated. Silicon nitride formed by low pressure chemical vapor deposition （LPCVD） was used as the masking layer for the island array formation. After etching, the microstructures were examined by a scanning electron microscope and the optical properties were studied by Fourier transform infrared spectroscopy, the result indicates that the multilayer structure could be obtained in the perpendicular direction via periodically alternative etching current in each pre-pattern. At the same time, the island array has a well-proportioned lateral etching effect, which is very useful for the thermal isolation in lateral orientation of the application in devices. It is concluded that regardless of the absorption of the deposition layer on the substrate, the localized photonic crystalline islands have higher reflectivity. The designed islands structure not only prevents the cracking of the porous silicon layers but is also useful for the application in the cold part for the sensor devices and the iliterconnection of each pixel.     

中红外波段硅基两维光子晶体的光子带隙

利用电化学腐蚀的方法制备了大多孔硅两维光子晶体.结构图形对称性为正方格子，其结构参数为正方形晶格周期a=44μm，正方形空气柱的边长l=2μm.并用显微红外光谱仪表征了光谱性质，揭示了所制备两维光子晶体样品的中红外波段光子的反射特性. 关键词： 光子晶体 光子带隙 反射谱 时域有限差分法     

An Improved Room-Temperature Silicon Terahertz Photodetector on Sapphire Substrates

We design and fabricate a good performance silicon photoconductive terahertz detector on sapphire substrates at room temperature.The best voltage responsivity of the detector is 6679 V/W at frequency 300 GHz as well as low voltage noise of 3.8 nV/Hz~(1/2) for noise equivalent power 0.57 pW/Hz~(1/2).The measured response time of the device is about 9 μs,demonstrating that the detector has a speed of110 kHz.The achieved good performance,together with large detector size(acceptance area is 3μm×160μm),simple structure,easy manufacturing method,compatibility with mature silicon technology,and suitability for large-scale fabrication of imaging arrays provide a promising approach to the development of sensitive terahertz room-temperature detectors.     

一种新型光电材料──β－FeSi_2的结构，光电特性及其制备

Ｂ－ＦｅＳｉ２是近年来发展起来的新型硅基光电材料。详细介绍了Ｂ－ＦｅＳｉ２的结构，电学、光学性质以及它的制备技术。对目前存在的问题以及未来的研究动向作了简要的讨论。