适用于表面分析的小型低能电子显微镜

A Compact Low Energy Electron Microscope for Surface Analysis

介绍并表征了一套单法兰集成的低能电子显微镜．这套显微镜中采用了10°偏转角的磁分束器，从而有利于将其集成到一个10in的法兰上．电子光学系统中的一些修正单元被简化，以使其结构简单，容易操作．样品被置于地电位，方便各静电透镜浮在高电压上．通过几个实验展示了这台显微镜在典型的低能电子成像、低能电子衍射和光电子成像模式下的性能．低能电子成像的空间分辨率为51nm．利用飞秒激光做光源，相应的非线性光电子发射过程使得这台设备非常适合进行光学近场现象的观察，并获得110nm的光电子成像空间分辨率．

The description and function characterization of a flange-on type low energy electron mi- croscope are given. In this microscope a magnetic beam separator with 10° deflection angle is used in order to facilitate compacting the instrument on a single 10 in. flange. Mean- while some correcting elements in the electron optical system are simplified to reduce the complexities of construction and operation. The sample is set close to ground potential, so that all the electrostatic lenses are easily to float at high voltages. The performance of the microscope in typical low energy electron microscopy, low energy electron diffraction and photoemission electron microscopy modes is demonstrated through several experiments. A lateral resolution of 51 nm is estimated for low energy electron microscopy imaging. With femtosecond laser as light source, the consequent nonlinear photoemission makes this micro-scope also suitable for the observation of optical near field phenomena and a lateral resolution of 110 nm is obtained.