【作者】 林桂江；

【导师】 余金中；

【作者基本信息】 厦门大学 ， 凝聚态物理， 2008， 博士

【摘要】 Si微电子技术已取得巨大成功,然而由于体材料Si的间接带隙特性,发光效率比直接带隙的GaAs等化合物材料低五个量级,如何在硅基材料系实现高效率发光,已成为发展硅基光电子学的一个重要课题,突破Si间接带隙限制的一条有希望的道路,是利用能带工程,使用Si/SiGe量子阱中的子带跃迁代替体材料中的带间跃迁。近年来,基于子带跃迁机理的硅基高效中远红外光电器件成为国内外学术界和产业界的一个研究热点。由于硅基光电子技术重大的产业背景,硅基高效中远红外光电子器件将具有更广泛的应用前景,对我国科技、工业和国防的发展具有重要的意义。本论文就是在这种背景下开展基于价带空穴子带跃迁、Si/SiGe量子级联激光器和Si/SiGe量子阱远红外探测器的基础研究,主要工作和研究成果有:(1)使用六带的k·p方法系统地研究了应变Si/SiGe材料的价带能带结构和空穴有效质量,定量计算分析了P型高掺杂Si/SiGe量子阱中的载流子分布、空穴子带跃迁矩阵元和量子阱空穴子带跃迁光吸收特性。(2)进行基于空穴子带跃迁中远红外(含太赫兹)Si/SiGe量子级联激光器能带设计研究,使用Drude模型和FDTD方法计算了长波长Si/SiGe量子级联激光器波导的限制因子和损耗特性,得到同时具有高限制因子和低损耗系数的长波长Si/SiGe量子阱级联激光器结构。(3)研究了基于空穴束缚态和准束缚态跃迁模型、应变Si/SiGe量子阱红外探测器的能带结构和品质因子。在国际上首次提出并从理论上论证使用张应变Si/SiGe量子阱红外探测器结构具有更高的吸收系数、更好的载流子输运特性和高探测灵敏度。(4)探讨了使用UHV/CVD系统进行Si/SiGe量子阱红外探测器的材料结构生长的若干问题,在600℃生长温度下,得到高质量Si/SiGe量子阱红外探测器的材料结构。提出一种方法用于估算Si/SiGe量子阱各层生长速率和组分,实验证明这种方法可以方便、准确地估算各种生长条件下Si/SiGe量子阱各层的生长速率和Ge组分,还可以估算源气体进入生长室到稳定生长所需要的时间。(5)研究正入射型Si/SiGe量子阱红外探测器的制备工艺,进行Si/SiGe量子阱红外探测器FTIR红外吸收谱测试和分析,得到吸收峰处于大气传输窗口3～5微米波段的量子阱红外探测器结构。更多还原

【Abstract】 People have won tremendous successes in silicon microelectronic technique,but, bulk silicon,with a indirect bandgap has a five order of magnitude lower light emission efficiency than direct bandgap materials such as GaAs.So,how to realize high light emission efficiency of silicon-based materials is one of the important topics concerning the development of silicon-based optoelectronics.Energy band engineering by using the intersubband transition in Si/SiGe quantum wells has been recognized as one of promising approaches to achievement of efficient light emission from silicon-based materials.In last few years,high-performance silicon-based mid-/far- infrared optoelectronic devices attracted more attention in academe and industry.It is therefore tremendously important to carry out such works for developing science,technology and industry for national defense in our country.Against this major background,a basic study has been carried out on Si/SiGe quantum cascade lasers and Si/SiGe quantum well infrared detectors based on hole intersubband transitions.The main work and results are summarized as follows:1.The valence band structures and hole effective masses of strained Si/SiGe materials are systematically studied by using the 6×6 k·p method.Holes occupation in the highly Boron doped quantum wells,the momentum matrix elements and optical absorption of intersubband transition between two hole states have been numerically calculated.2.The energy band design and operational mechanism of Si/SiGe quantum cascade lasers(QCLs) at mid-/far- infrared(terahertz) frequency are discussed.By using Drude model and FDTD method,high confinement factor of Si/SiGe QCLs work at THz frequency are obtained with low loss coefficients.3.Designs for strained p-type Si/SiGe quantum well infrared photodetectors(QWIPs) based on the bound-to-quasi-bound transitions are discussed,the figure-of-merit of this kind of Si/SiGe QWIPs have beed calcuated.We proposed on tensile strained p-type QWIPs for the first time,which are expected to retain the ability to couple normally incident infrared radiation without any grating couplers,with lower dark current than that of n-type QWIPs and larger absorption coefficient and better transport characteristics than those of normal unstrained or compressive strained p-type QWIPs.4.High quality Si/SiGe QWIP structures were expitaxially grown by using UHV/CVD system.A method was developed to evaluate the growth rates and Ge compositions of Si/SiGe quantum wells.The equilibration time for the source gases to deposit on Si substrate can also be evaluate by this method.5.Infrared absorption spectra of the Si/SiGe QWIP structures have been measured and the QWIP devices were fabricated.The FTIR measuremmts show that the Si/SiGe QWIP structure has a strong absorption at 3～5μm,this wavelength range is one of the Earth’s atmosphere in the transparent spectral regions.更多还原