Si基Ⅳ族异质结构发光器件的研究进展  

Recent progress in Ge and GeSn light emission on Si

作　　者：何超[1] 张旭[1] 刘智[1] 成步文[1] 

机构地区：[1]中国科学院半导体研究所,集成光电子学国家重点实验室,北京100083

出　　处：《物理学报》2015年第20期27-36,共10页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(批准号:2013CB632103);国家自然基金(批准号:61176013,61036003)资助的课题~~

摘　　要：Si基光互连具有高速度、高带宽、低功耗、可集成等特点,有望解决集成电路的集成度在日益提高时电互连带来的问题.在Si基光互连的关键器件中,除了Si基光源尚未得到解决,其他器件都已经实现,因此Si基可集成高效光源具有十分重要的研究意义.同为Ⅳ族元素的Ge和GeSn因其与Si的可集成性及其独特的能带结构有望成为Si基光电集成回路中的光源.虽然Ge是间接带隙材料,但通过引入张应变、n型重掺杂,或者引入Sn形成GeSn合金等能带工程手段来提高发光效率.近年来,Si基Ⅳ族发光材料和发光器件有许多重要进展,本文就Si基Ge,GeSn材料发光研究中的几个关键技术节点——应变工程、掺杂技术、理论模型和器件研究——回顾了近几年国际和国内的研究进展,并展望了Si基Ⅳ族激光器的发展趋势.Si-based optical interconnection is expected to solve the problems caused by electric interconnection with increasing the density of integrated circuits,due to its merits of high speed,high bandwidth,and low consumption.So far,all of the key components except light source of Si-based optical interconnection have been demonstrated.Therefore,the light source has been considered as one of the most important components.Ge and GeSn based on Si have emerged as very promising candidates because of their high compatibility with Si CMOS processing,and the pseudo direct-bandgap characteristic.The energy difference between the direct and indirect bandgap of Ge is only 136 meV at room temperature.Under tensile strain or incorporation with Sn,the energy difference becomes smaller,and even less than zero,which means that Ge or GeSn changes into direct bandgap material.What is more,using large n-type doping to increase the fraction of electrons in r valley,we can further increase the luminous efficiency of Ge or GeSn.In this paper,we briefly overview the recent progress that has been reported in the study of Ge and GeSn light emitters for silicon photonics,including theoretical models for calculating the optical gain and loss,several common methods of introducing tensile strain into Ge,methods of increasing the n-type doping density,and the method of fabricating luminescent devices of Ge and GeSn.Finally,we discuss the challenges facing us and the development prospects,in order to have a further understanding of Ge and GeSn light sources.Several breakthroughs have been made in past years,especially in the realizing of lasing from GeSn by optically pumping and Ge by optically and electrically pumping,which makes it possible to fabricate a practical laser used in silicon photonics and CMOS technology.

关 键 词：SI基 Ge GeSn 发光器件 

分 类 号：TN304.12[电子电信—物理电子学]