非晶铟镓锌氧化物薄膜晶体管制备工艺及性能研究  

STUDY ON FABRICATION PROCESS AND PROPERTIES OF AMORPHOUS INGAZNO THIN FILM TRANSISTOR

作　　者：刘丽 吕腾博 刘嘉乐 程乾 王小力[2,3] LIU Li;LV Tengbo;LIU Jiale;CHENG Qian;WANG Xiaoli(Normal College,Shenyang University,Shenyang,Liaoning 110044,China;School of Microelectronics,Xi'an Jiaotong University,Xi'an,Shaanxi 710049;School of Science,Xi'an Jiaotong University,Xi'an,Shaanxi 710049)

机构地区：[1]沈阳大学师范学院,辽宁沈阳110003 [2]西安交通大学微电子学院,陕西西安710049 [3]西安交通大学物理学院,陕西西安710049

出　　处：《物理与工程》2024年第3期178-185,共8页Physics and Engineering

基　　金：陕西省重点研发计划项目(2023-YBSF-407)。

摘　　要：本文介绍了利用射频磁控溅射技术在氧化硅衬底上制备非晶氧化铟镓锌(a-IGZO)薄膜,对溅射的薄膜进行了不同条件下的特性分析,制备成a-IGZO薄膜晶体管(a-IGZO TFT),并分别研究了溅射气氛、有源层厚度和退火工艺对器件电学性能的影响。实验表明,当使用50W的溅射功率时,溅射过程中补充氧气,可以填补材料的深能级氧空位缺陷,提高了器件性能。但氧气浓度过大也会造成吸附氧等受主缺陷增多,更易发生载流子的散射,实验中采用氩氧比为Ar∶O2=24∶1.2的条件器件性能较好。其次,当有源层厚度控制在40~50nm时,器件性能较好,且40nm的薄膜性质更佳。最后,高温退火工艺可以改善薄膜的缺陷,消除薄膜内部原有应力。相比氮气退火条件,将薄膜在空气下退火可以实现更好的电学特性,将40nm的薄膜在空气下400℃退火30min,a-IGZO TFT的性能达到最佳,其迁移率为15.43cm^(2)/(V·s),阈值电压为13.09V,电流开关比为7.3×10^(8),为将来制备晶圆级的高迁移a-IGZO TFT奠定了基础。The present study reports on the fabrication of amorphous InGaZnO(a-IGZO)thin films on silicon oxide substrates using radio-frequency magnetron sputtering technique,and investigates their characteristics under different conditions.Subsequently,a-IGZO thin-film transistors(a-IGZO TFT)were prepared and their electrical properties were studied in relation to the effects of sputtering atmosphere,active layer thickness,and annealing process.The experimental findings demonstrate that,when using a sputtering power of 50W,the performance of the device can be improved by introducing supplemental oxygen into the sputtering process,which effectively mitigates the deep-level oxygen vacancy defects in the material.However,an excessive concentration of oxygen may give rise to an increase in the number of acceptor defects,such as adsorbed oxygen,which promotes carrier scattering.Based on our investigation,we determined that the device exhibited optimal performance when the argon-oxygen ratio was maintained at Ar∶O2=24∶1.2.Secondly,optimal performance of the de-vice is achieved by controlling the thickness of the active layer within the range of 40~50nm,with the film properties peaking at a thickness of 40nm.Finally,the application of high-tem-perature annealing process serves to alleviate the defects of the film,while also effectively eliminating any internal stresses that may exist within the film.In comparison with nitrogen annealing conditions,annealing a-IGZO films under an air environment leads to superior elec-trical properties.Specifically,annealing a 40nm-thick film at 400℃for 30 minutes in air re-sulted in the optimal performance of the a-IGZO TFT device,with a recorded mobility of 15.43cm^(2)/(V·s),a threshold voltage of 13.09 V,and a current switching ratio of 7.3×10^(8).These findings establish a solid foundation for future endeavors towards the preparation of wa-fer-level high-mobility a-IGZO TFTs.

关 键 词：铟镓锌氧化物 薄膜晶体管 磁控溅射 有源层厚度 退火 

分 类 号：TN321.5[电子电信—物理电子学]