提出了一种检测光刻机投影物镜密集线焦深(DOF)的新技术。该技术将具有精细结构的测量标记曝光在硅片上，硅片显影后，由光学对准系统获取曝光在硅片上的测量标记图形的对准位置信息，根据对准位置信息计算得到视场中各点的焦深。与传统的FEM焦深测试技术相比，该技术具有测量精度高、速度快、成本低、操作简单等优点，在光刻工艺参数优化及光刻设备性能评价等方面有很好的应用前景。

A novel method for measuring dense-line depth of focus (DOF) of a lithographic projection system is proposed. In the method, special marks are exposed on a silicon wafer, and then printed on it after being developed. The printed images of these marks are aligned by an optical alignment system and the alignment positions of the images are recorded. From the above information, the DOF can be obtained. Compared with focus expoxuse matrix (FEM) method, the novel method has the advantages of higher measurement accuracy, faster measuring, less cost and simpler operations. The method can be widely used in optimizing the lithographic process parameters and evaluating the characteristics of lithographic projection systems.