印刷电路板激光投影成像照明系统均匀性分析  

Uniformity analysis of the illumination system for PCB laser projection image

作　　者：裴文彦[1] 周金运[2] 梁国均[2] 林清华[2] 

机构地区：[1]广东工业大学实验教学部,广东广州510006 [2]广东工业大学物理与光电工程学院,广东广州510006

出　　处：《量子电子学报》2009年第3期360-365,共6页Chinese Journal of Quantum Electronics

基　　金：广东省自然科学基金(07001789);广东省科技计划项目(2007B010400071);广州市科技计划项目(2006Z3D0041)

摘　　要：针对351 nm波长的XeF准分子激光器,自行设计了用于高精度、高产率、大面积且常规抗蚀剂曝光的印刷电路板(PCB)激光投影成像照明系统。根据准分子激光的部分相干平顶高斯光束(PCFGB)理论模型,对微透镜阵列器(MLA)均束的衍射特性进行了理论分析。由PCFGB分布函数、稳定光强输出的衍射角和菲涅耳-基尔霍夫衍射积分公式,定量分析衍射效应对MLA均束的影响。理论计算表明,微透镜边缘发生菲涅耳衍射和微透镜产生的多光束干涉都能引起光振幅调制,只不过衍射产生的尖峰更明显地出现在光束边缘。同时,由数值积分得到的PCFGB曲线,发现9×9 MLA均束器既能保证多个微透镜产生光束叠加的均匀性,又最大程度地减少了衍射和多光束干涉效应。通过采取加正六边形光阑的方法,不仅能满足大面积无缝扫描光刻的需要,而且能剪裁由衍射引起的光束边缘尖峰。由ZEMAX光学设计软件模拟其效果,显示其加工窗不大于士2%。For 351 nm XeF excimer, an illumination system for PCB laser projection image used for high resolution, high throughput, large area and conventional photoresists exposure is designed. On the basis of the theory model of the excimer＇s partly coherent flat-top Gaussian beam （PCFGB）, the diffractive characteristic of micro-lens array （MLA） homogenizer is theoretically analyzed. The uniformity of MLA homogenizer influenced by the diffractive effect is quantitatively analyzed by means of distribution of PCFGB, diffractive angles of constant intensity and Fresael-Kirchhoff diffractive integral formula. The theoretical calculation indicates that the amplitude is modulated not only by Fresnel diffraction at the microlenses edges but also by multiple beam interference, and it is just obvious that the spikes produced by diffraction emerge in the beam edges. Meanwhile, for the PCFGB curves obtained by numerical integral, it is found that 9 × 9 MLA homogenizer can ensure the overlapping uniformity of the beams from individual microlenses and decrease the effect of the diffraction and multiple beam interference to a great extent. By way of using a hexagonal diaphragm, the spikes at the beam edges produced by diffraction can be cut down and the large-area seamless scanning lithography met. Using ZEMAX optical design software to simulate the effect, it shows that the process window is less than ±2% .

关 键 词：激光技术 均束器 激光投影成像光刻 XeF准分子激光 印刷电路板 加工窗 

分 类 号：TN248[电子电信—物理电子学]