为了提高移相点衍射干涉仪对193 nm 投影光刻系统的检测精度，本文对其主要测量误差进行了探讨。在简要介绍了193 nm 移相点衍射干涉仪的基本结构和测量原理之后，总结了可能对测量结果产生影响的各种误差及其产生的原因。通过理论分析和数值模拟的方法分别对参考波前误差、相移误差、探测器非线性误差以及光源波动、环境变化引起的随机误差等进行了具体分析，从而得到各种测量误差的大小、存在形式以及与干涉仪结构参数的依赖关系，并提出了相应的避免或减小误差的方法。

To improve the measurement accuracy, the main measurement errors of the 193-nm Phase-shifting Point Diffraction Interferometer (PS/PDI) are discussed here. The elementary configuration and measuring principle of the 193-nm phase-shifting point diffraction interferometer are introduced firstly. Then different kinds of measurement errors and their causes are summed up, including reference wave front error, geometrical separation induced error, phase-shifting error, grating error, and errors caused by CCD, laser source and fluctuating surroundings and so on. The magnitude and shapes of these measurement errors, together with the connections between these errors and the configuration parameters of the interferometer, are all obtained through detailed analysis and simulation. For the sake of avoiding or restraining these errors, some methods are put forward accordingly.