使用溅射AlN成核层实现大规模生产深紫外LED

高质量AlN薄膜对制造高性能深紫外器件非常重要,但是目前还很难使用大型工业MOCVD生长出高质量的AlN薄膜.采用磁控溅射制备了不同厚度的用作成核层的AlN薄膜,使用大型工业MOCVD直接在成核层上高温生长AlN外延层,研究了不同成核层对AlN外延层质量的影响.通过扫描电子显微镜和原子力显微镜对成核层AlN薄膜的表面形貌进行表征;使用高分辨X射线衍射仪对AlN外延层晶体质量进行表征,结果表明:在溅射成核层上生长的AlN外延层的晶体质量有显著提高.使用大型工业MOCVD在蓝宝石衬底上成功制备出中心波长为282 nm的可商用深紫外LED,在注入电流为20 mA时,单颗深紫外LED芯片的光输出功率达到了1.65 mW,对应的外量子效率为1.87%,饱和光输出功率达到4.31 mW.

Large-Scale Production of Deep UV-LEDs by Using Sputtered AlN Nucleation Layer

High-quality AlN film are indispensable for high performance deep ultraviolet devices.However,it is still difficult to use the high-yield industrial MOCVD to grow high-quality AlN thin films.The AlN film with different thicknesses were prepared as the nucleation layer by the magnetron sputtering.The AlN epitaxial layers were grown directly on these nucleation layers at high temperatme by the highyield industrial MOCVD system.The effects of different nucleation layers on the quality of the AlN epitaxial layers were investigated.The surface morphologies of AlN nucleation layers were characterized by the scanning electron microscope and atomic force microscope.The crystal quality of AlN epitaxial layers was characterized by the high resolution X-ray diffractometer.The results show that the crystalline quality of AlN epitaxial layers grown on the sputtering AlN nucleation layer is significantly improved.Commercial deep UV-LEDs with the center wavelength of 282 nm were successfully prepared on the sapphire substrate by the high-yield industrial MOCVD.The light-output power of a single deep UV-LED reaches 1.65 mW at the injection current of 20 mA with the external quantum efficiency of 1.87%,and the saturation lightoutput power of the deep UV-LED reaches 4.31 mW.