公开(公告)号：US20130100427A1

公开(公告)日：2013-04-25

申请号：US13628697

申请日：2012-09-27

Applicant: ASML Netherlands B.V.

Inventor： Armand Eugene Albert KOOLEN ,  Henricus Petrus Maria Pellemans ,  Maurits Van Der Schaar ,  Peter Clement Paul Vanoppen ,  Michael Kubis

IPC: G03B27/54 ,  G01N21/47

CPC classification number: G03F1/42 ,  G01B9/04 ,  G01N21/47 ,  G03F7/70616 ,  G03F7/70633 ,  G03F9/70 ,  G03F9/7069 ,  G03F9/7088

Abstract: An approach is used to estimate and correct the overlay variation as function of offset for each measurement. A target formed on a substrate includes periodic gratings. The substrate is illuminated with a circular spot on the substrate with a size larger than each grating. Radiation scattered by each grating is detected in a dark-field scatterometer to obtain measurement signals. The measurement signals are used to calculate overlay. The dependence (slope) of the overlay as a function of position in the illumination spot is determined. An estimated value of the overlay at a nominal position such as the illumination spot's center can be calculated, correcting for variation in the overlay as a function of the target's position in the illumination spot. This compensates for the effect of the position error in the wafer stage movement, and the resulting non-centered position of the target in the illumination spot.

Abstract translation: 一种方法用于估计和校正覆盖变化作为每个测量的偏移函数。 形成在衬底上的靶包括周期性光栅。 在衬底上用圆形点照射衬底，其尺寸大于每个光栅。 在暗场散射仪中检测由每个光栅散射的辐射，以获得测量信号。 测量信号用于计算叠加。 确定覆盖层与照明点中位置的函数关系（斜率）。 可以计算在诸如照明点中心的标称位置处的覆盖物的估计值，以根据目标在照明点中的位置的函数来校正覆盖物的变化。 这补偿了晶片台移动中的位置误差的影响，以及目标在照明点中产生的非居中位置。