提出了一种新的光刻机像质参数热漂移原位检测技术(TDFM)。详细分析了该技术利用镜像测试标记检测投影物镜最佳焦面热漂移与放大倍率热漂移的基本原理。实验结果表明TDFM技术可同时实现最佳焦面热漂移(FFT)与放大倍率热漂移(MFT)的精确测量。与现有的放大倍率热漂移检测技术相比,该技术有效地解决了放大倍率热漂移技术中放大倍率热漂移受最佳焦面热漂移影响的问题,简化了光刻机像质参数前馈校正的测试过程,测试成本与耗时均减少50%。

During the exposure of lithography tools, the performance of the projection lens is shown to be dependent on the amount of the energy absorbed. A novel technique for measuring the thermal drifts of imaging parameters of the lithographic projection systems is proposed. The principle for measuring the thermal drifts of focus and magnification (TDFM) based on mirror-symmetry marks is described in this paper. Through experiments, it is demonstrated that thermal drifts of best focus and magnification of the projection systems can be obtained with high accuracy by the technique. Compared to magnification fine tune (MFT), the conventional technique used for thermal drift measurement of magnification, TDFM has the advantages of considering the influences of the process factors on the lateral displacements and decreasing the time of thermal drifts measurement. The cost and the time of thermal drifts measurement are both decreased by 50%.