电子束曝光系统鞍形线圈的偏转象差与绕线分布

THE DEFLECTION ABERRATION AND WINDING DISTRIBUTION OF SADDLE-TYPE DEFLECTOR FOR ELECTRON BEAM LITHOGRAPHY SYSTEM(EBLS)

本文对扫描电子束曝光系统(SEBLS)透镜后偏转鞍形线圈的三级偏转像差对电子光柱系统的重要参数:偏转器与透镜之间的距离Z_o,工作距离Z_s以及对偏转器几何形状参数L/R的关系进行了较系统的分析;对绕线分布的影响(包括绕线中心位置、绕线宽度及绕线对称性对象差的影响)的计算结果指出:当鞍形磁偏转器(Saddle-type)以π/6为中心两侧对称布线时,因绕线分布所产生的偏转像差影响在微米、亚微米曝光系统中可以忽略。根据上述原理,我们研制成功一??种高精度WEDM偏转器,它有效的介决了CAD优化设计实际绕线工艺之间的一致性问题,这一偏转器的性能及其优越性,已在我们的微米圆束机中得到证实。

The paper present investigates the relation between the third orderdeflection aberration and important parameters of electron optical column ofEBLS,including:the distance Z_o referred to deflector and objective lens,working distance Z_s as well as geometrycal parameter of deflection coils R/L.The calculated results of winding distribution show that π/6 central angle ofthe winding and larger variance of the winding width the influence of thirdorder aberration is negligible in micro EBLS and submicron EBLS. A new type of deflector was fabricated using above results (WEDM deflec-tor) .This deflector indicates consistency between the CAD and the actualstructure of the windings.The performance and advantages of WEDMdeflector wsa obtained in our micro lithography system.