热退火处理对AuGeNi/n-AlGaInP欧姆接触性能的影响  

Study on the effect of thermal annealing process on ohmic contact performance of AuGeNi/n-AlGaInP

作　　者：王苏杰 李树强 吴小明 陈芳 江风益 Wang Su-Jie;Li Shu-Qiang;Wu Xiao-Ming;Chen Fang;Jiang Feng-Yi(National Institute of LED on Si Substrate,Nanchang University,Nanchang 330047,China)

机构地区：[1]南昌大学国家硅基LED工程技术研究中心

出　　处：《物理学报》2020年第4期269-276,共8页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2016YFB0400600,2016YFB0400601,2016YFB0400603)资助的课题

摘　　要：本文在n-(Al0.27Ga0.73)0.5In0.5P表面通过电子束蒸发Ni/Au/Ge/Ni/Au叠层金属并优化退火工艺成功制备了具有较低接触电阻的欧姆接触,其比接触电阻率在445℃退火600 s时达到1.4×10–4 W·cm2.二次离子质谱仪测试表明,叠层金属Ni/Au/Ge/Ni/Au与n-AlGaInP界面发生固相反应,Ga,In原子由于热分解发生外扩散并在晶格中留下Ⅲ族空位.本文把欧姆接触形成的原因归结为Ge原子内扩散占据Ga空位和In空位作为施主提高N型掺杂浓度.优化退火工艺对低掺杂浓度n-(Al0.27Ga0.73)0.5In0.5P的欧姆接触性能有显著改善效果,但随着n-(Al0.27Ga0.73)0.5In0.5P掺杂浓度提高,比接触电阻率与退火工艺没有明显关系.本文为n面出光的AlGaInP薄膜发光二极管芯片的n电极制备提供了一种新的方法,有望大幅简化制备工艺,降低制造成本.In this paper,Ni/Au/Ge/Ni/Au laminated metals were deposited on the n-(Al0.27Ga0.73)0.5In0.5P by electron beam evaporation,the ohmic contact with low contact resistance was successfully prepared by optimized annealing process.The specific contact resistance reached 1.4×10–4 W·cm2 when annealed at 445℃for 600 s.The result of the secondary ion mass spectrometer shows that the solid-state reaction takes place at the interface between the laminated metal Ni/Au/Ge/Ni/Au and n-AlGaInP,then the germanium atoms and indium atoms diffuse outwards due to thermal decomposition and leave vacancies in the lattice.In this paper,the reason for the formation of ohmic contact is attributed to the fact that the germanium vacancy and indium vacancy are occupied by gallium atoms as donors to increasing the N-type doping concentration.The optimized annealing process can improve the ohmic contact performance of n-(Al0.27Ga0.73)0.5In0.5P with low doping concentration,but the specific contact resistivity has no obvious relationship with the annealing process when the of doping concentration of n-(Al0.27Ga0.73)0.5In0.5P increased.The Schottky barrier is high at low doping concentration of n-(Al0.27Ga0.73)0.5In0.5P.So inter diffusion in the annealing process could significantly increase the doping concentration of n-(Al0.27Ga0.73)0.5In0.5P and reduce the Schottky barrier height.Nevertheless,the Schottky barrier of the sample with high doping concentration is low enough what is not sensitive with inter diffusion.It provides a new method for the preparation of N-electrode of AlGaInP thin film light-emittingdiodes chip,as so as avoid the problem of n+-GaAs absorption in the conventional N-electrode preparation method and the problem of electrode dropping.However,there are still some shortcomings in this paper.The disadvantage is that the high doping concentration of n-AlGaInP will affect the crystal quality,which will reduce the luminous efficiency of LED.Therefore,in order to prepare ohmic contact with excellent properties on n-AlGaInP

关 键 词：ALGAINP 欧姆接触 退火工艺 发光二极管 

分 类 号：TG156.2[金属学及工艺—热处理] TB383.2[金属学及工艺—金属学] TN312.8[一般工业技术—材料科学与工程]