Ti/n型6H-SiC(0001)接触界面的研究

用同步辐射光电子能谱(SRPES)和X射线光电子能谱(XPS)的方法研究了Ti/n型6H-SiC(0001)的接触界面。Ti/n型6H-SiC(0001)样品采用磁控溅射的方法获得,然后将表面的Ti用氩离子刻蚀的方法慢慢刻蚀掉,Ti2p3/2用XPS测得,结合能从刻蚀时间为245 min的457.86 eV逐渐移动到刻蚀时间为255 min时的457.57 eV,移动约为0.3 eV。Si2p用同步辐射光测得,结合能从刻蚀245 min时的101.12 eV移动到干净的100.67 eV,峰形状未发生变化,表明Ti与衬底之间没有发生化学反应,SiC的价带发生弯曲,形成的势垒高度为0.89 eV。向SiC上蒸Si 2.5 min,退火30 min,观察LEED花样,发现当发射电流为30mA,能量37 eV时,SiC表面有√3*√3重构,发射电流为40 mA时,有6√3*6√3的重构。

Formation and Characterization of Ti/n-Type 6H-SiC(0001) Interface

Here,we addressed the formation and property of the Ti/ n-Type 6H-SiC(0001) interface.The contact junction was fabricated by Ti magnetron sputtering on SiC(0001) substrate,followed by Ar ion sputtering.The microstructures and electronic properties at the interface were characterized with synchronized radiation photoelectron spectroscopy,X-ray photoelectron spectroscopy,and low energy electron microscopy(LEED).When the ion etching time varied from 245 min to 255 min,the binding energy of the XPS Ti2p3/2 core level peak was found to shift by 0.3 eV,from 457.86 eV to 457.57 eV.After etching for 245 min,the binding energy of SRPES Si2p core level peak shifted from 101.11 eV to 100.67 eV,showing that the clean SiC surfaces were reached.The peak remained stable,and no Ti silicide formation was observed.A Schottky barrier height,originated from the SiC band bending,was found to be 0.89 eV.After annealing of the as-deposited Si layer on SiC surface,LEED reconstruction patterns were clearly observed,indicating a fairly clean and well-define SiC surfaces.