硅基Ⅳ族材料外延生长及其发光和探测器件研究进展

硅基光电集成回路是信息时代最具影响力的核心技术之一,由硅基光源、光电探测器、光调制器等模块组成.硅材料是微电子集成电路的基石,然而在光电集成方面却遇到了瓶颈.首先,由于硅是间接带隙材料,其发光效率极低,因此难以应用于硅基高效光源的研制.其次,硅在近红外通讯波段吸收系数很低,因此在近红外光电探测器的应用中具有较大的局限性.然而,研究者发现,通过能带工程将硅与其他Ⅳ族材料相融合不仅可以有效提高直接带高效发光效率,同时能使材料在近红外波段具有较高的吸收系数.因此,以Ⅳ族材料为基础,与硅工艺兼容的硅基光电集成回路引起了研究者的广泛关注.本文综述了课题组在硅基材料外延生长及其发光和探测器件方面的研究进展.介绍了硅基Ⅳ族材料Ge,SiGe/Ge异质结和量子阱材料的外延生长技术,以及硅基GeSn量子点发光材料的制备新方法.基于硅基Ⅳ族异质结构材料,发展调制金属与半导体接触势垒高度新机理,研制了多种结构的光电探测器.设计并制备了与互补金属氧化物半导体(Complementary Metal Oxide Semiconductor,CMOS)结构兼容的横向异质结以及双有源区垂直共振腔型两种结构硅基电致发光器件,有效提升器件的发光性能,并观察到应变锗发光增益现象.

Research progress in the epitaxial growth of silicon-based groupⅣmaterials,and their light emitters and photodetectors

Silicon-based optoelectronic integrated circuits,which are composed of silicon-based light sources,photodetectors,light modulators,and other modules,are core technologies in the recent information era.Silicon is the cornerstone of microelectronic integration,but it encounters issues with optoelectronic integration.First,as an indirect bandgap material,silicon is difficult to be used in high-efficiency light sources,which is still currently the biggest challenge.Second,the absorption coefficient of silicon in the near-infrared communication band is very low,so it is not suitable for the near-infrared photodetectors.Silicon-compatible groupⅣmaterials can achieve direct band through band engineering.They have a high absorption coefficient in the near-infrared and have attracted extensive attention of researchers.In this paper,the research progress of epitaxial growth of silicon-based materials,and their light emitters and photodetectors,are reviewed.The growth technologies of Ge,Si Ge/Ge heterojunction,quantum wells,and Ge Sn quantum dots are introduced.Based on the above silicon-based groupⅣheterostructure materials,a new method for modulating the height of the contact barrier between metal and semiconductor was proposed.Also,various photodetectors with different structures were developed.The lateral heterojunction LED and vertical resonant-cavity LED,including dual active regions compatible with traditional CMOS processes,were developed.The luminescence performance of the devices was improved effectively and the luminescence gain of strain Ge was observed.