氧化铟锡与掺Fe半绝缘GaN的接触特性  

Contact Characteristics of Indium Tin Oxide with Fe Doped Semi-Insulated GaN

作　　者：卫新发 梁国松 张育民[2,3] 王建峰 徐科[1,2,3] Wei Xinfa;Liang Guosong;Zhang Yumin;Wang Jianfeng;Xu Ke(School of Nano-Tech and Nano-Bionics,University of Science and Technology of China,Hefei 230026,China;Key Laboratory of Nanophotonic Materials and Devices,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,China;Suzhou Nanowin Science and Technology Co.,Ltd.,Suzhou,215123,China)

机构地区：[1]中国科学技术大学纳米技术与纳米仿生学院,合肥230026 [2]中国科学院苏州纳米技术与纳米仿生研究所纳米光子材料与器件重点实验室,江苏苏州215123 [3]苏州纳维科技有限公司,江苏苏州215123

出　　处：《半导体技术》2021年第6期474-478,共5页Semiconductor Technology

基　　金：国家重点研发计划资助项目(2017YFB0404101)。

摘　　要：氧化铟锡(ITO)透明电极能够有效提高GaN光导半导体开关的光吸收效率和电场均匀性,但如何在透明电极ITO与半绝缘GaN之间实现良好的欧姆接触是一个难题。通过在ITO和半绝缘GaN之间插入与GaN功函数相近的Ti薄层,并利用快速热退火过程加速Ti与GaN之间的反应。研究发现Ti薄层的厚度和退火温度对欧姆接触有重要影响。在Ti薄层厚度为5 nm时,随着退火温度的升高,ITO/Ti/GaN之间的接触逐渐转变为欧姆接触,且接触电阻率随之减小;但当退火温度超过700℃时,欧姆接触变差,这与ITO中的In、Sn和O元素向界面扩散有关;适当提高Ti薄层的厚度可以有效改善ITO/Ti/GaN欧姆电极的热稳定性,但过厚的Ti薄层会对GaN基光电器件的透过率产生影响。Indium tin oxide(ITO)transparent electrodes can effectively improve the light absorption efficiency and electric field uniformity of GaN photoconductive semiconductor switches,but how to achieve a good ohmic contact between the transparent electrode ITO and semi-insulated GaN is a challenge.By inserting a Ti thin layer with similar work function to that of GaN between ITO and semi-insulated GaN,following by a rapid thermal annealing process,the reaction between Ti and GaN was accelerated.It is found that the thickness of the Ti thin layer and annealing temperature have an important effect on the ohmic contact.When the thickness of the Ti thin layer is 5 nm,the contact between ITO/Ti/GaN gradually changes to ohmic contact with the increase of annealing temperature,and the contact resistivity is decreased.However,the ohmic contact becomes worse when the annealing temperature exceeds 700℃,which is related to the diffusion of In,Sn and O elements in ITO to the interface.The Ti thin layer with appropriate thickness can effectively improve the thermal stability of the ITO/Ti/GaN ohmic electrode,but the Ti thin layer with an excessive thickness will affect the transmittance of GaN-based optoelectronic devices.

关 键 词：掺Fe GaN 氧化铟锡(ITO) Ti薄层 欧姆接触 热稳定性 光导半导体开关 

分 类 号：TN304[电子电信—物理电子学]