公开(公告)号：US20020021460A1

公开(公告)日：2002-02-21

申请号：US09907902

申请日：2001-07-19

申请人： Silicon Valley Group, Inc.

发明人： Matthew E. Hansen

IPC分类号： G03H001/00

CPC分类号： G03F7/706 ,  G03F7/70375 ,  G03F7/70616

摘要： Characterization of an optical system is quickly and easily obtained in a single acquisition step by obtaining image data within a volume of image space. A reticle and image plane are positioned obliquely with respect to each other such that a reticle having a plurality of feature sets thereon, including periodic patterns or gratings, is imaged in a volume of space, including the depth of focus. Metrology tools are used to analyze the detected or recorded image in the volume of space through the depth of focus in a single step or exposure to determine the imaging characteristics of an optical system. Focus, field curvature, astigmatism, spherical, coma, and/or focal plane deviations can be determined. The present invention is particularly applicable to semiconductor manufacturing and photolithographic techniques used therein, and is able to quickly characterize an optical system in a single exposure with dramatically increased data quality and continuous coverage of the full parameter space. In embodiments, the test reticle is holographically generated by interfering two or more beams of optical radiation. The resulting interference pattern is recorded on a reticle and used for testing the optical system. The geometry of the holographic interference pattern is tightly controlled by the properties of the interfering beams and is therefore more accurate than conventional reticle writing techniques.

摘要翻译： 通过在图像空间的体积内获得图像数据，在单个采集步骤中快速且容易地获得光学系统的表征。 掩模版和图像平面相对于彼此倾斜地定位，使得其上包括周期性图案或光栅的具有多个特征集的掩模版被成像在包括焦深的空间体积中。 计量工具用于通过单步骤或曝光中的焦点深度来分析检测或记录的空间体积，以确定光学系统的成像特性。 可以确定焦点，场曲率，散光，球面，彗差和/或焦平面偏差。 本发明特别适用于其中使用的半导体制造和光刻技术，并且能够以单一曝光快速表征光学系统，并以显着增加的数据质量和全参数空间的连续覆盖。 在实施例中，通过干扰两个或更多个光辐射束来全息地产生测试掩模版。 所得到的干涉图案被记录在掩模版上并用于测试光学系统。 全息干涉图案的几何形状受到干涉光束的特性的严格控制，因此比传统的掩模版书写技术更精确。