Ti-DLC薄膜压阻性能及载流子输运行为研究  

Ti Doped Diamond Like Carbon Films:Piezoresistive Properties and Carrier Transport Behavior

作　　者：赵志翰 郭鹏 魏菁 崔丽 刘山泽 张文龙 陈仁德 汪爱英[2,3] ZHAO Zhihan;GUO Peng;WEI Jing;CUI Li;LIU Shanze;ZHANG Wenong;CHEN Rende;WANG Aiying(School of Materials Science and Chemical Engineering,Ningbo University,Ningbo 315211,China;Key Laboratory of Advanced Marine Materials,Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences,Ningbo 315201,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]宁波大学材料科学与化学工程学院,宁波315211 [2]中国科学院宁波材料技术与工程研究所,海洋关键材料重点实验室,宁波315201 [3]中国科学院大学材料与光电研究中心,北京100049

出　　处：《无机材料学报》2024年第8期879-886,I0001,I0002,共10页Journal of Inorganic Materials

基　　金：宁波市科技创新2025重大专项(2020Z023);国家自然科学基金(U20A20296,52205237);宁波市高新区重大技术创新项目(2021CCX050003)。

摘　　要：围绕压阻传感器领域对高性能类金刚石(Diamond Like Carbon,DLC)薄膜压阻敏感材料的需求,针对金属掺杂DLC存在的载流子输运行为和实际多工况(如温度、湿度等)下压阻性能不明的问题,本工作以Ti-石墨复合拼接靶为靶材,采用高功率脉冲磁控溅射技术,高通量制备出4种Ti含量(原子分数为0.43%~4.11%)的Ti掺杂类金刚石(Ti-DLC)薄膜,研究了Ti含量对薄膜组分结构、电学性能、变湿度环境下压阻性能的影响规律。结果表明:Ti含量(原子分数)在0.43%~4.11%范围内,掺杂Ti原子均以固溶形式均匀镶嵌于非晶碳网络中,Ti-DLC薄膜电学行为表现为典型半导体特性,在200~350 K温度范围内,薄膜电阻率均随温度升高而降低。载流子传导机制在200~270 K内为Mott型三维变程跳跃传导,在270~350 K范围内则为热激活传导。Ti-DLC薄膜压阻系数(Gauge Factor,GF)最大值为95.1,在20%~80%相对湿度范围内,所有样品GF均随湿度增加而增大,这可能是引入的固溶Ti原子缩短了导电相之间的平均距离,同时吸附表面水分子导致电阻变化。Diamond like carbon(DLC)film was a promising candidate for microelectromechanical system(MEMS)piezoresistive sensors owing to its excellent mechanical properties and sensitivity.The effects of carrier transport behavior and the role of operating conditions(such as temperature,humidity,etc.)on piezoresistive performance of metal-doped DLC were still unclear.In this work,Ti doped diamond like carbon(Ti-DLC)films with Ti atom fraction ranging from 0.43%to 4.11%were prepared using high-power pulse magnetron sputtering,where the high-throughput conception was introduced for film deposition.Effects of the doped Ti content on microstructure,electrical behavior and piezoresistive properties of the films were studied under various humidity environments.The results indicated that the doped Ti atoms were uniformly dissolved in the diamond like carbon matrix,accompanying typical amorphous characteristics for the Ti-DLC films regardless of Ti atom fraction changing from 0.43%to 4.11%.Furthermore,all the Ti-DLC films demonstrated distinct semiconductor feature,where the electrical resistivity was reduced with the increase of temperature in the range of 200-350 K.Particularly,the carrier transport was dominated by Mott type conduction with three-dimensional range hopping conduction from 200 to 270 K,while the thermal activation transport served as the conductive mechanism in the temperature range of 270-350 K.For the Ti-DLC films,the highest gauge factor(GF)was 95.1,and GF value increased with increasing relative humidity from 20%to 80%.This can be explained from reduction of the average distance between conductive cluster by introducing Ti atoms and a change in electrical resistance caused by adsorption of water molecules.

关 键 词：Ti掺杂 类金刚石薄膜 电学性能 可变湿度 压阻行为 

分 类 号：TQ174[化学工程—陶瓷工业]