高质量的AlGaN外延结构和UVC垂直腔面发射激光器的实现  

High-quality AlGaN epitaxial structures and realization of UVC verticalcavity surface-emitting lasers

作　　者：郑重明 王玉坤 胡建正 郭世平 梅洋 龙浩 应磊莹 郑志威 张保平 Zhongming Zheng;Yukun Wang;Jason Hoo;Shiping Guo;Yang Mei;Hao Long;Leiying Ying;Zhiwei Zheng;Baoping Zhang(Department of Electronic Engineering,Optoelectronics Engineering Research Center,School of Electronic Science and Engineering(National Model Microelectronics College),Xiamen University,Xiamen 361005,China;Advanced Micro-Fabrication Equipment Inc.,Shanghai 201201,China)

机构地区：[1]Department of Electronic Engineering,Optoelectronics Engineering Research Center,School of Electronic Science and Engineering(National Model Microelectronics College),Xiamen University,Xiamen 361005,China [2]Advanced Micro-Fabrication Equipment Inc.,Shanghai 201201,China

出　　处：《Science China Materials》2023年第5期1978-1988,共11页中国科学（材料科学（英文版）

基　　金：supported by the National Key Research and Development Program of China(2017YFE0131500);the National Natural Science Foundation of China(62104204 and U21A20493)。

摘　　要：AlGaN基垂直腔面发射激光器(VCSEL)因其优越的材料性质和器件优点吸引了很多关注.然而,由于材料外延生长和器件制备工艺的局限,AlGaN基VCSEL制备很困难.本工作通过侧向外延生长技术制备了高质量的AlGaN多量子阱(MQWs)结构的外延片,并通过X射线衍射(XRD)和光致发光(PL)实验对外延片进行了分析.XRD测量显示,外延片中的AlN模板层几乎是弛豫的,刃位错密度为10^(9)cm^(-2).随后,生长的AlGaN/AlN超晶格(SL)层被用来减少刃位错密度,使得量子阱中的位错密度为10^(8)cm^(-2).根据PL测试结果,MQWs的内量子效率(IQE)为62%,且在室温下的发光以辐射复合为主.通过激光剥离(LLO)和化学机械抛光(CMP)技术,将这些外延片制备成UVC VCSEL.经过这些工艺,MQWs的晶体质量没有受到影响,还在抛光之后的表面观察到了UVC波段的受激辐射.这些AlGaN基UVC VCSEL在275.91,276.28和277.64 nm实现了激射,最小激射阈值为0.79 MW cm^(-2).AlGaN-based vertical-cavity surface-emitting lasers(VCSELs)have garnered recent interest due to their superior material properties and device benefits.Nevertheless,AlGaN-based VCSELs are extremely difficult to realize due to numerous technical limitations associated with both material epitaxial growth and chip fabrication.This study fabricated a high-quality AlGaN multiple quantum wells(MQWs)structure using epitaxial lateral overgrowth and analyzed it using X-ray diffraction(XRD)and photoluminescence(PL)measurements.With an edge dislocation density(DD)of 10^(9)cm^(−2),XRD measurements reveal that the AlN template is nearly fully relaxed.The subsequent AlGaN/AlN superlattice(SL)layer is introduced to decrease the edge DD,and the edge DD in the MQWs is~10^(8)cm^(−2).According to PL measurements,the internal quantum efficiency of the MQWs is as high as 62%,and radiative recombination dominated the emission of the MQWs at room temperature.Using these epitaxial wafers,ultraviolet radiation C(UVC)VCSELs were fabricated using various techniques,including laser lift-off(LLO)and chemical mechanical polishing(CMP).The crystallinity of the MQWs was unaffected by sapphire substrate removal using LLO.After removing the sapphire substrate using LLO and CMP,UVC surface-stimulated emission was observed in MQWs.AlGaN-based UVC VCSELs with lasing wavelengths of 275.91,276.28,and 277.64 nm have been fabricated.The minimum threshold for UVC VCSELs is 0.79 MW cm^(−2),which is a record low.

关 键 词：ALGAN vertical-cavity surface-emitting lasers epitaxial lateral overgrowth laser lift-off UVC 

分 类 号：TQ133.1[化学工程—无机化工] TN248[电子电信—物理电子学]