Accuracy enhancement for optical metrology

The invention relates to accuracy enhancement of optical metrology. The invention provides a method for improving the accuracy of metrology measurement, a metrology module and a target design. The method provides for flexible handling of a plurality of measurement prescriptions and settings and enables correlating the plurality of measurement prescriptions and settings with atlas features indicative of their relationships with resonance regions and flat regions. Clustering of prescriptions, self consistency testing, co-processing of aggregated measurements, noise reduction, cluster analysis, detailed analysis of maps and targets with skewed cells are employed, alone or in combination, to provide a cumulative increase in measurement accuracy. 本公开涉及光学计量的准确度提升。本发明提供提升计量测量的准确度的方法、计量模块及目标设计。方法提供对多个测量处方及设置的灵活处置且使得能够使所述多个测量处方及设置与指示其与谐振区域及平坦区域的关系的图谱特征相关。单独地或以组合方式采用对处方的群集化、自身一致性测试、对经汇总测量的共同处理、噪声降低、群集分析、对具有偏斜单元的图谱及目标的详细分析，以提供测量准确度的累积提升。