刻蚀改变InGaN/AlGaN应变多量子阱发光特性  

Photoluminescence of InGaN/AlGaN Strained Multiple Quantum Wells Influenced by Dry Etching

作　　者：曹萌[1] 吴惠桢[1] 劳燕锋[1] 刘成[1] 谢正生[1] 

机构地区：[1]中国科学院上海微系统与信息技术研究所信息功能材料国家重点实验室

出　　处：《光学学报》2007年第3期494-498,共5页Acta Optica Sinica

基　　金：国家重点基础研究计划(973计划;2003CB314903)的资助课题。

摘　　要：为了分析干法刻蚀对应变多量子阱(SMQWs)发光特性的影响,采用感应耦合等离子体(ICP)刻蚀技术对金属有机物化学气相沉积(MOCVD)生长的InGaN/AIGaN应变多量子阱覆盖层表面刻蚀了约95 nm。通过光致发光(PL)特性表征发现,干法刻蚀后量子阱光致发光强度较未刻蚀量子阱光致发光强度提高了近3倍。干法刻蚀后,量子阱表面呈现高低起伏状形貌,粗糙度提高,出射光在起伏状粗糙形貌表面反复散射,从而逃逸概率增大,有助于光致发光强度增强。理论计算结果得出表面形貌变化引起的量子阱光致发光强度增强因子约为1．3倍。另外,由于所采用的感应耦合等离子体功率较小,刻蚀损伤深度几乎不会达到量子阱阱层,然而干法刻蚀过程中Ar离子隧穿到量子阱阱层内部可能形成新的发光中心,从而使量子阱的发光强度得到提高。To investigate the influence of dry etching on strained multiple quantum wells （SMQWs）, we etch the cap layer of metalorganic chemical vapor phase deposition （MOCVD） grown InGaN/AIGaN SMQWs about 95 nm by inductively coupled plasma （ICP）. Photoluminescence （PL） measurements show that, the photoluminescence intensity of the quantum wells is enhanced about 3 times after dry etching. The surface of the quantum well becomes fluctuant, the degree of roughness becomes larger, and it allows the photons generated within the quantum wells to escape surface more easily by multiple scattering at the rough surface. The theoretic calculation result shows that the pattern change of the quantum well surface causes the enhancement of the photoluminescence intensity about 1.3 times. On the other side, because the inductively coupled plasma power is small, the damage depth almost cannot reach the well layer, but the tunneling of Ar^＋ inside the quantum well structure may bring new luminescence centers, and enhances the photoluminescence intensity.

关 键 词：光学材料 应变多量子阱 干法刻蚀 损伤 光致发光 

分 类 号：TN383.1[电子电信—物理电子学]