【摘要】 基于纳米曝光要求和JSM-35CF型扫描电镜,设计了一组上下偏转器长度不一致的静电偏转器,使偏转灵敏度大大提高。采用二阶有限元法计算了八极静电偏转器的轴上场分布。高精度的场分布有利于高级像差。为了使系统的总体像差最小,结合具体电子光学系统,用最小二乘法对偏转器的激励强度、转角及其在系统中的位置进行优化,得到直至五级分量的像差。动态校正后,偏转场为80μm×80μm时,束斑分辨率约为3.2nm;偏转场大小为1mm×1mm时,束斑分辨率约为29.8nm。结果表明,应用该组静电偏转器的电子光学系统的分辨率满足纳米曝光的要求。更多还原

【Abstract】 Based on JSM-35CF scaning microscope,we design a set of electrostatic deflectors with different lengths. Compared with conventional deflectors with the same lengths,the deflectors we designed are of higher sensitivity. We compute the field in electrostatic deflectors using the second-order finite element method.High-accuracy field make us compute high-order aberrations conveniently.In order to make the system has the lowest aberrations we optimized the optical properties using the least squares method, including the third-order and fifth-order aberrations by varying the axial positions, relative strengths and the rotation angles of the deflectors. Resolution of the system is 3.2 nm in field with 80 μm×80 μm and 29.8 nm in field with 1 mm×1 mm. Results from the simulation show that the resolution of the electron beam system with these electrostatic deflectors meets the requirement of the nanometer lithography.更多还原