调焦调平传感器增益系数工艺相关性研究  

Gain Coefficient Process Dependency of Focusing and Leveling Sensor

作　　者：孙生生 王丹[1] 宗明成[1,2] Sun Shengsheng;Wang dan;Zong Mingcheng(Institute of Microelectronics,Chinese Academy of Sciences,Beijing 100029,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院微电子研究所,北京100029 [2]中国科学院大学,北京100049

出　　处：《光学学报》2022年第4期101-108,共8页Acta Optica Sinica

基　　金：国家科技重大专项(2017ZX02101006)。

摘　　要：针对先进光刻调焦调平传感器系统的增益系数工艺相关性开展理论仿真与实验研究。建立了增益系数工艺相关性理论模型,仿真分析了调焦调平传感器增益系数与测量误差随不同光刻工艺材料膜层厚度的变化规律。在自研实验系统上对表面涂覆不同厚度SiO_(2)薄膜的硅片样品进行了实验验证,发现实验与理论仿真得到的增益系数与测量误差随膜层厚度的变化规律一致。仿真与实验研究结果表明,调焦调平传感器的工艺相关性测量误差在SiO_(2)膜层厚度为250 nm和690 nm附近时分别出现约55.9 nm和36.6 nm的误差峰值。采用表面覆盖特定膜层的硅片来标定光刻机调焦调平传感器,可以有效减小增益系数工艺相关性的影响和测量误差。本研究结果对于光刻精密对焦控制、光刻工艺优化具有重要的参考意义。In this paper,the theoretical simulation and experimental investigation are carried out on the gain coefficient process dependency of the advanced lithography focusing and leveling sensor.The theoretical model of gain coefficient process dependency was established to simulate and analyze the variations in the gain coefficient and measurement error of the focusing and leveling sensor with the film thickness of different materials for lithography process.The silicon wafers coated with SiO_(2) films of different thicknesses were tested in our self-developed experimental system.The experimental results of variations in the gain coefficient and the measurement error with the film thickness are consistent with the theoretical simulation results.Simulation and experimental results show that the process dependency measurement error of the focusing and leveling sensor has the peak values about 55.9 nm and 36.6 nm at the SiO_(2) film thicknesses of 250 nm and 690 nm,respectively.Using the silicon wafer coated with the specific film to calibrate the focusing and leveling sensor of the lithography machine can considerably reduce the effect of the gain coefficient process dependency and its measurement error.The investigation results of this paper can be used as reference to optimize the focusing control and lithography process.

关 键 词：测量 调焦调平传感器 增益系数 工艺相关性 对焦控制 

分 类 号：O436[机械工程—光学工程]