GaAs/GaAlAs光阴极的XPS深度剖析  

X-Ray Photoelectron Spectroscopy Study of Depth Profile of GaAs/GaAlAs Photocathode

作　　者：冯刘[1,2] 张连东[1,2] 刘晖[1,2] 程宏昌[1,2] 高翔[1,2] 陈高善[1,2] 史鹏飞[1,2] 苗壮[1,2] 

机构地区：[1]微光夜视技术重点实验室,西安710065 [2]北方夜视科技集团有限公司,昆明650223

出　　处：《真空科学与技术学报》2013年第8期803-807,共5页Chinese Journal of Vacuum Science and Technology

摘　　要：GaAs光阴极是一种高性能光阴极,它由GaAs/GaAlAs外延片和玻璃基底粘接而成。为了了解外延片的元素深度分布和各层的均匀性,利用X射线光电子能谱和Ar离子刻蚀来进行深度剖析。结果表明,由于送样过程中曾短暂暴露大气,因而GaAs光阴极表面吸附有少量C、O污染,并且GaAs表层被氧化;GaAs层中的Ga、As元素含量非常均匀,约为3∶2,富Ga;而GaAlAs层中的Ga、Al和As含量比约为1∶1∶2,Ga略少于Al,但稍大于Ga0.42Al0.58As的比例。Ar离子枪采用3kV、1μA模式,刻蚀面积1 mm×1 mm,结合C-V测试得到的各层厚度数据,可以计算出该模式下各层的刻蚀速率,GaAs层的刻蚀速率约为1.091 nm/s,而GaAlAs层约为0.790 nm/s,并且推算出GaAs的溅射产额为4.00,GaAlAs的溅射产额为2.90。The GaAs photocathode,consisting of the epitaxial layers of GaAlAs on GaAs substrate bonded on glass plate,was fabricated.The depth profile of the GaAs/GaAlAs photocathode was analyzed with X-Ray photoelectron spectroscopy（XPS） and argon sputtering etching.The impacts of the sputtering conditions,including the Ar-beam energy,ion current,and etching rate,on the depth profile were experimentally studied.The preliminary results show that the short exposure to the air of the GaAs photocathode,in loading the sample into the vacuum chamber,significantly affected the surfaces.For example,oxidized layers,and contamination of C and O on the surfaces of the GaAs photocathode were observed.The stoichiometric ratio of Ga and As in the Ga rich,fairly uniform GaAs layers was approximately 3∶2;and that of the Ga,Al and As in the GaAlAs layer was about 1∶1∶2,with Ga a little lower than that of Al,but higher than the ratio in Ga0.42Al0.58As.

关 键 词：深度剖析 GAAS X射线光电子能谱 刻蚀速率 溅射产额 

分 类 号：TH838.3[机械工程—仪器科学与技术]