Intermittent failure mechanism and stabilization of microscale electrical contact  

作　　者：Tianbao MA Zhiwei YU Aisheng SONG Jiahao ZHAO Haibo ZHANG Hongliang LU Dandan HAN Xueyan WANG Wenzhong WANG 

机构地区：[1]State Key Laboratory of Tribology,Tsinghua University,Beijing 100084,China [2]Inspur Beijing Electronic Information Industry Co.,Ltd.,Beijing 100085,China [3]Department of Precision Instrument,Tsinghua University,Beijing 100084,China [4]Innovation Center for Future Chips,Beijing 100084,China [5]State Key Laboratory of Precision Measurement Technology and Instruments,Beijing 100084,China [6]School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China [7]School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China [8]Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Friction》2023年第4期538-545,共8页摩擦（英文版）

基　　金：support of the National Natural Science Foundation of China(Grant Nos.11890671,61774096,and 51935006);National Science and Technology Major Project(2017-VII-0013-0110);the Fundamental Research Funds for the Central Universities.

摘　　要：The stability and lifetime of electrical contact pose a major challenge to the performance of microelectro-mechanical systems(MEMS),such as MEMS switches.The microscopic failure mechanism of electrical contact still remains largely unclear.Here conductive atomic force microscopy with hot switching mode was adopted to simulate the asperity-level contact condition in a MEMS switch.Strong variation and fluctuation of current and adhesion force were observed during 10,000 repetitive cycles,exhibiting an“intermittent failure”characteristic.This fluctuation of electrical contact properties was attributed to insulative carbonaceous contaminants repetitively formed and removed at the contact spot,corresponding to degradation and reestablishment of electrical contact.When contaminant film was formed,the contact interface became“metal/carbonaceous adsorbates/metal”instead of direct metal/metal contact,leading to degradation of the electrical contact state.Furthermore,a system of iridium/graphene on ruthenium(Ir/GrRu)was proposed to avoid direct metal/metal contact,which stabilized the current fluctuation and decreased interfacial adhesion significantly.The existence of graphene enabled less adsorption of carbonaceous contaminants in ambient air and enhanced mechanical protection against the repetitive hot switching actions.This work opens an avenue for design and fabrication of microscale electrical contact system,especially by utilizing two-dimensional materials.

关 键 词：atomic force microscopy microscale electrical contact GRAPHENE 

分 类 号：U472[机械工程—车辆工程]