摘要
极紫外光刻光学检测通常使用光纤点衍射干涉仪,光纤衍射的圆偏振态光束可以提高干涉条纹的对比度、减小衍射球面波的像散,对于提高检测精度有十分重大意义。用穆勒矩阵分析了相位控制型偏振控制器的工作原理,得到只需两个控制通道就可以调控到圆偏振态的结论。设计了光纤点衍射干涉仪球面参考源的偏振控制系统,并用琼斯矩阵分析了光束经过偏振控制系统后的光强变化,得到光强最小时两个控制通道的控制电压。在理论分析基础上搭建了球面参考源的偏振控制系统,获得了圆偏振态所需的控制电压,并将其输入偏振控制器调控得到圆偏振光,实验结果表明此方法可以在不引入额外误差的同时,快速地实现圆偏振态的调节,并且理论计算与实际的误差不超过7.5%,证明了该方法的可行性。
Fiber point diffraction interferometer meets the accuracy of optical test for extreme ultraviolet lithography （EUVL）. Wavefront reference source which emits circularly polarization state light can enhance the contrast of interference fringes and reduce the astigmation of wavefront reference source. The principle of phase- controlled polarization controller is analyzed by Mueller matrix and found to obtain circularly polarization by only using the first two control channels. A polarization control system has been designed, and the light intensity is analyzed after propagating from the polarization control system by Jones matrix. The control voltage of the first two control channels are obtained. A polarization control system is built and a circularly polarization light is achieved. The error between theory and reality is about 7.5 %, which is verified by analyzing the first two control channel before polarization control test. The polarization of wavefront reference source is controlled into circularly polarization quickly, thus the problem of polarization control is solved for fiber diffraction interferometer.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2014年第11期128-134,共7页
Acta Optica Sinica
基金
应用光学国家重点实验室基金(09Q03FQM90)
关键词
光学设计
极紫外光刻
光纤点衍射
球面参考源
偏振控制
optical design
extreme ultraviolet lithography
fiber point diffraction interference
wavefrontreference source
polarization control
