APPARATUS AND METHOD FOR MEASURING SUBSTRATE HEIGHT

An apparatus for measuring a height of a substrate for processing in a lithographic apparatus is disclosed. The apparatus comprises a first sensor for sensing a height of the substrate over a first area. The apparatus also comprises a second sensor for sensing a height of the substrate over a second area. The apparatus further comprises a processor adapted to normalize first data corresponding to a signal from the first sensor with a second sensor footprint to produce a first normalized height data, and to normalize second data corresponding to a signal from the second sensor with a first sensor footprint to produce a second normalized height data. The processor is adapted to determine a correction to a measured height of the substrate based on a difference between the first and second normalized height data. 公开了一种用于测量用于在光刻设备中进行处理的衬底的高度的设备。所述设备包括用于感测所述衬底在第一区域范围内的高度的第一传感器。所述设备还包括用于感测所述衬底在第二区域范围内的高度的第二传感器。所述设备还包括处理器，所述处理器适于：以第二传感器覆盖区对与来自所述第一传感器的信号相对应的第一数据作归一化，以产生第一归一化高度数据，以及以第一传感器覆盖区对与来自所述第二传感器的信号相对应的第二数据作归一化，以