扫描电镜条件对不导电样品表面荷电现象的影响  

Effect of SEM Conditions on Charging Phenomenon on The Surface of Non-conductive Samples

作　　者：汪一聪 王丹 李嘉铭 余红华 江丹 曾丽珍 孙峰 Wang Yicong;Wang Dan;Li Jiaming;Yu Honghua;Jiang Dan;Zeng Lizhen;Sun Feng(Analysis&Testing Center,South China Normal University,Guangzhou 510006;Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices,School of Information and Optoelectronic Science and Engineering,South China Normal University,Guangzhou 510006,China)

机构地区：[1]华南师范大学分析测试中心,广东广州510006 [2]华南师范大学信息光电子科技学院,广东省微纳光子功能材料与器件重点实验室,广东广州510006

出　　处：《广东化工》2022年第11期216-219,227,共5页Guangdong Chemical Industry

摘　　要：利用扫描电镜对不锈钢板与玻璃板激光焊接样品不经镀膜直接进行显微观察。扫描电镜分别梯度设置一系列一次电子加速电压与E-T二次电子探测器前端栅网上的一系列偏压,观察样品表面荷电现象的变化。结果表明:在同样的加速电压下,上述栅网偏压越低,样品表面的荷电现象越弱,当栅网偏压降低至足够低时荷电现象消失。另外,在加速电压越低时,刚好足够令荷电现象消失的栅网偏压越高,此时电镜条件有利于图像质量的改善。对上述栅网偏压对荷电现象的影响机理给出了解释——栅网偏压影响探测器接收二次电子与背散射电子数量的比例,进而影响荷电现象的轻重。A laser welding sample of stainless steel and glass is observed with SEM without coating.A gradient series of primary electron acceleration voltages and collector bias voltages of the E-T SE detector of the SEM are set respectively for observing the changing of charging phenomenon on the sample surface.The result shows that with the same acceleration voltage,the lower the collector bias voltage is,the weaker the charging phenomenon is.Especially,when the collector bias voltage is low enough,the charging phenomenon disappears.Furthermore,the lower the acceleration voltage is,the higher the collector bias voltage which is just low enough to make the charging phenomenon disappear is,bringing an improvement to the conditions of the SEM for a better image quality.The mechanism of the effect of the above collector bias voltage on the charging phenomenon is explained as follows:the collector bias voltage affects the ratio between the amounts of SE and BSE captured by the detector,which in turn affects the level of the charging phenomenon.

关 键 词：扫描电镜 荷电现象 E-T二次电子探测器 栅网偏压 二次电子 背散射电子 

分 类 号：TN16[电子电信—物理电子学]