纳米氮化钛薄膜对高频陶瓷窗片二次电子发射率的影响研究

Effect of Titanium Nitride Nanofilms on the Secondary Emission Yield of High Frequency Ceramic Windows

纳米TiN薄膜可用来抑制高频陶瓷窗片的二次电子倍增,缩短器件高功率老炼时间,提高微波发射性能。文章通过专用真空镀膜设备,采用同轴圆柱靶和平面靶的直流磁控反应溅射方法,通过优化制备工艺参数,在陶瓷窗片的表面成功制备了纳米氮化钛(TiN)薄膜。采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)等现代分析手段进行了测试分析,结果表明:纳米TiN薄膜表面晶粒细小,致密度较好;晶面(111)和(200)特征衍射峰峰型规整,峰宽细窄;Ti/N原子计量比接近于1∶1。随着薄膜沉积时间增加,二次电子发射系数(SEY)逐渐增大,溅射时间8.4 s时,SEY为1.72;随着基体偏压的增加,电离效率增加,SEY不断降低,当偏压为350 V时,SEY为1.89;随着N2流量增加,SEY发生变化,当N2流量为38 mL/min时,SEY为1.83。

Nano TiN films can be used to inhibit the secondary electron multiplication of high frequency ceramic windows,shorten the high power aging time of devices,and improve microwave emission performance.In this paper,nano-titanium nitride(TiN)films were successfully prepared on the surface of ceramic windows by using the DC magnetron reaction sputtering method of coaxial cylindrical target and planar target by special vacuum coating equipment and optimizing the preparation process parameters.Modern analytical methods such as scanning electron microscope(SEM),X-ray diffractometer(XRD)and X-ray photoelectron spectrometer(XPS)were used for testing and analysis.The results show that the surface of the TiN film has fine grain size and good density.The crystal planes(111)and(200)feature diffraction peaks with regular peak shapes and narrow peak widths.The atomic stoichiometric ratio of Ti/N is close to 1∶1.With the increase of the deposition time of the film,the secondary electrons emission coefficient(SEY)gradually increases,and SEY is 1.72 when the sputtering time is 8.4s.With the increase of matrix bias,the ionization efficiency increases,and SEY decreases continuously.When the bias voltage is 350 V,the SEY is 1.89.With the increase of nitrogen flow,SEY changed,and when the N2 flow was 38 mL/min,the lowest SEY was 1.83.