双光栅叠栅条纹对准方法具有精度高、可靠性强等特点，适用于接近接触式光刻。为了实现高精度测量，实际应用中要求掩模光栅标记与硅片光栅标记高度平行。掩模光栅标记在CCD中成像通常存在一定的倾斜角。由此，在已提出的相位斜率倾斜条纹标定方法上，提出了一种改进方法。该方法充分利用掩模光栅45°和135°两个方向的相位信息标定CCD的成像位置，以实现掩模光栅条纹的标定。对比两种方法分析表明，改进后的方法具有倾角测量范围大、抗噪性强、精度高等优点，理论极限精度优于0.001°量级。

The alignment method of dual-grating Moiré fringe has characteristics of high-accuracy and reliability, which is mainly fit for contact and proximity lithography. For the realization of high-accuracy measurement, the parallelism between mask grating mark and wafer grating mark is practically required. Generally, mask grating mark imaged in CCD has a tiny inclined angle. Therefore, an improved method is proposed, based on the previously proposed calibration method for inclined fringes through phase slope. The improved method makes full use of phase information in directions of 45° and 135° to revise the imaging position of CCD. By this mean, the mask grating fringes are also calibrated. Through comparison between the two methods, the results imply that the improved method is provided with large-measurement scope, strong anti-noise and high-accuracy, and measurement accuracy is better than 0.001° level.