光刻物镜硅片刻蚀过程中的Z5像散会使光刻物镜波像差产生严重的劣化。为了对像散进行实时补偿, 提出一种Z5像散主动补偿系统。该系统由实时数据平台、驱动力系统、柔性支撑结构和光学透镜构成。采用球面干涉仪作为光学透镜表面面形的检测设备, 利用最小二乘法及线性叠加原理确定驱动参数与面形关系。实验进行了主动补偿系统的驱动器响应函数测试、补偿行程测试、补偿精度测试、补偿分辨率测试。结果表明, 系统Z5像散补偿行程达到735 nm, Z5像散补偿精度小于2 nm, 引入的高阶像差小于1 nm, 像散补偿分辨率为2 nm, 该系统能够有效补偿光刻物镜系统波前像差, 使光刻物镜满足像质要求。

The astigmatism Z5 in the etching process of lithographic lens silicon wafer can greatly deteriorate wave aberration of the lithographic lens. In order to compensate the astigmatism in real time, this paper proposes an astigmatism active Z5 compensation system that includes real time data platform, actuator system, flexible supporting structure and optical lens. The sphere interferometer is used as test equipment for optical lens surface shape. The least square method and the linear superposition principle are both used to determine the relationship between actuate parameter and surface shape. The experiments, including test of response function of actuator in active compensation system, test of compensation stroke, test of compensation precision, test of compensation resolution, are conducted. The results show that the astigmatism Z5 compensation stroke of the system is up to 735 nm. The astigmatism Z5 compensation precision is less than 2 nm with the high-order aberration less than 1 nm. The astigmatism Z5 compensation resolution is 2 nm. The system can effectively compensate the wave aberration in the lithographic lens system and satisfy the image quality requirement of lithographic lens.