公开(公告)号：US20110027704A1

公开(公告)日：2011-02-03

申请号：US12846652

申请日：2010-07-29

申请人： Hugo Augustinus Joseph Cramer ,  Arie Jeffrey Den Boef ,  Henricus Johannes Lambertus Megens ,  Hendrik Jan Hidde Smilde ,  Andrianus Johannes Hendrikus Schellekens ,  Michael Kubis

发明人： Hugo Augustinus Joseph Cramer ,  Arie Jeffrey Den Boef ,  Henricus Johannes Lambertus Megens ,  Hendrik Jan Hidde Smilde ,  Andrianus Johannes Hendrikus Schellekens ,  Michael Kubis

IPC分类号： G03F7/20 ,  G03B27/54 ,  G06K9/00

CPC分类号： G03F7/70641 ,  G01B11/02 ,  G01B11/22 ,  G01B11/24 ,  G01B11/30 ,  G01N21/47 ,  G01N21/88 ,  G03F7/70608 ,  G03F7/70625 ,  G03F7/70633 ,  G03F7/7065

摘要： In a method of determining the focus of a lithographic apparatus used in a lithographic process on a substrate, the lithographic process is used to form a structure on the substrate, the structure having at least one feature which has an asymmetry in the printed profile which varies as a function of the focus of the lithographic apparatus on the substrate. A first image of the periodic structure is formed and detected while illuminating the structure with a first beam of radiation. The first image is formed using a first part of non-zero order diffracted radiation. A second image of the periodic structure is foamed and detected while illuminating the structure with a second beam of radiation. The second image is formed using a second part of the non-zero order diffracted radiation which is symmetrically opposite to the first part in a diffraction spectrum. The ratio of the intensities of the measured first and second portions of the spectra is determined and used to determine the asymmetry in the profile of the periodic structure and/or to provide an indication of the focus on the substrate. In the same instrument, an intensity variation across the detected portion is determined as a measure of process-induced variation across the structure. A region of the structure with unwanted process variation can be identified and excluded from a measurement of the structure.

摘要翻译： 在确定在基板上的光刻工艺中使用的光刻设备的焦点的方法中，使用光刻工艺在基板上形成结构，该结构具有至少一个特征，该特征在印刷图案中具有不对称性 作为光刻设备在基板上的焦点的函数。 在用第一辐射束照射结构的同时形成和检测周期性结构的第一图像。 第一图像使用非零阶衍射辐射的第一部分形成。 周期性结构的第二图像被发泡并被检测，同时用第二辐射束照射结构。 使用在衍射光谱中与第一部分对称相对的非零级衍射辐射的第二部分形成第二图像。 确定测量的第一和第二部分光谱的强度的比率并用于确定周期性结构的轮廓的不对称性和/或提供焦点在基底上的指示。 在相同的仪器中，被检测部分的强度变化被确定为整个结构的过程引起的变化的量度。 可以从结构的测量中识别并排除具有不期望的工艺变化的结构区域。