Step-confined thin film growth via near-surface atom migration  

作　　者：Caixia Meng Junfeng Gao Rongtan Li Yanxiao Ning Yuan Chang Rentao Mu Qiang Fu Xinhe Bao 

机构地区：[1]State Key Laboratory of Catalysis,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian,116023,China [2]University of Chinese Academy of Sciences,Beijing,100039,China [3]Key Laboratory of Materials Modification by Laser,Ion and Electron Beams,Dalian University of Technology,Ministry of Education,Dalian,116024,China [4]University of Science and Technology of China,Hefei,230026,China

出　　处：《Nano Research》2020年第6期1552-1557,共6页纳米研究（英文版）

基　　金：This work was financially supported by the National Natural Science Foundation of China(Nos.21688102,21573224,and 21825203);the National Key R&D Program of China(Nos.2016YFA0200200 and 2017YFB0602205);Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB17020000);the Start-Up funding of DUT(No.3005-852069).

摘　　要：Understanding of thin film growth mechanism is crucial for tailoring film growth behaviors,which in turn determine physicochemical properties of the resulting films.Here,vapor-growth of tungsten carbide overlayers on W(110)surface is investigated by real time low energy electron microscopy.The surface growth is strongly confined by surface steps,which is in contrast with overlayer growth crossing steps in a so-called carpet-like growth mode for example in graphene growth on metal surfaces.Density functional theory calculations indicate that the step-confined growth is caused by the strong interaction of the forming carbide overlayer with the substrate blocking cross-step growth of the film.Furthermore,the tungsten carbide growth within each terrace is facilitated by the supply of carbon atoms from near-surface regions at high temperatures.These findings suggest the critical role of near-surface atom diffusion and step confinement effects in the thin film growth,which may be active in many film growth systems.

关 键 词：thin film growth tungsten carbide near-surface dopant low-energy electron microscopy(LEEM) step confinement 

分 类 号：O64[理学—物理化学]