n-GaN上Au/Zr和Au/Ti金属电极的界面反应和金属间互扩散行为对比研究  

Comparison Study on the Interfacial Reaction and Intermetallic Interdiffusion Behavior of Au/Zr and Au/Ti Metal Electrodes on n-GaN

作　　者：张可欣 李庚伟 杨少延 魏洁[4] ZHANG Kexin;LI Gengwei;YANG Shaoyan;WEI Jie(School of Science,China University of Geoscience(Beijing),Beijing 100083,China;University of Chinese Academy of Sciences,Materials and Optoelectronics Research Center,Beijing 100049,China;Key Laboratory of Semiconductor Materials Science,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;Nanjing Youtian Metal Technology Co.,Ltd.,Nanjing 211164,China)

机构地区：[1]中国地质大学(北京)数理学院,北京100083 [2]中国科学院大学材料与光电研究中心,北京100049 [3]中国科学院半导体研究所,半导体材料科学重点实验室,北京100083 [4]南京佑天金属科技有限公司,南京211164

出　　处：《材料导报》2022年第21期120-125,共6页Materials Reports

基　　金：国家自然科学基金(61774147);南京佑天金属科技有限公司技术开发项目(Y8H1020M00)。

摘　　要：电极接触是制作半导体器件中非常重要的问题。金属电极与半导体形成的欧姆接触是器件高效率、低功耗服务的保障,直接影响了器件性能的优劣。前人关于欧姆接触的研究主要集中在金属电极体系和处理条件的选择,寻求比接触电阻率最低的方案。而本工作突破桎梏,从欧姆接触的形成机制出发讨论金属欧姆接触的可行性,研究了低温(650℃)退火60 s和高温(850℃)退火30 s条件下,Au(300 nm)/Zr(30 nm)/n-GaN和Au(300 nm)/Ti(30 nm)/n-GaN结构的接触机理。采用紫外光刻法定义圆点型传输线模型,并且利用磁控溅射设备在GaN上制备金属电极样品,分析了电极样品的互扩散行为及界面反应情况。研究结果表明:与Au/Ti/n-GaN相比,Au/Zr/n-GaN样品受温度影响小,界面固相反应生成的Zr-N化合物热稳定性更优异,可以帮助器件在高温高压下更加稳定地工作;Zr与氮化镓接触时产生的Ga合金相更少,有利于器件利用隧道机制传输载流子;Au/Zr/n-GaN样品具有更小的界面孔隙,与氮化镓的界面反应适中;Au/Zr/n-GaN样品具有更平整的表面,适合大功率高电流工作。此外,根据本工作的对比研究可以得出:金属的制备与提纯、阻挡层金属的添加、制作金属电极的方法、势垒层金属的稳定性、金属与氮化镓的界面反应程度以及电极的表面粗糙度都会影响器件性能。Zr替代Ti作为n型GaN欧姆接触电极可以实现器件更高的性能要求,是一种具有广阔应用前景的金属材料,对于GaN器件的研发和改善有很大帮助。Electrode contact is a very important issue in making semiconductor devices.The ohmic contact generated by metal electrode and semiconductor is the guarantee of device service with high efficiency and low power consumption,which directly affects the performance of devices.Previous studies of ohmic contact mainly focused on the selection of metal electrode system and treatment conditions to look for the scheme with the lowest specific contact resistance.This work breaks through the shackles and discusses the feasibility of metal from the perspective of the formation mechanism of ohmic contact.The contact mechanism of Au(300 nm)/Zr(30 nm)/n-GaN and Au(300 nm)/Ti(30 nm)/n-GaN structure was studied under the conditions of annealing at 650℃for 60 s and 850℃for 30 s.UV lithography was adopted to define the dot transmission line model,and metal electrode samples were prepared on GaN with magnetron sputtering equipment.The counter-diffusion and interfacial reaction of electrode samples were analyzed.The results indicate that compared with Au/Ti/n-GaN,the Au/Zr/n-GaN samples are less affected by temperature,and the Zr-N compound generated by interfacial solid-state reaction has superior thermal stability,which can help the device work more stably at high temperature and high pressure;less Ga alloy phase is produced when Zr comes into contact with gallium nitride,which helps the device to transmit carriers with tunneling mechanism;the interface pores of Au/Zr/n-GaN samples are smaller and the interface reaction with gallium nitride is moderate;the surface of Au/Zr/n-GaN sample is more flat,which is suitable for the work with high power and high current.In addition,it can be comparatively concluded that the performance of the device will be affected by the preparation and purification of metal,adding barrier metal,the method of making metal electrode,the stability of barrier metal,the interface reaction degree between metal and gallium nitride,and the surface roughness of electrode.Higher performance requirements of the

关 键 词：N型GAN Au/Zr欧姆接触电极 互扩散行为 界面反应 

分 类 号：O472.4[理学—半导体物理]