US Patent 10495983 Piecewise alignment modeling method

Methods are provided and generally relate to adjusting exposure parameters of a substrate in response to an overlay error. The method includes partitioning the substrate into one or more sections. Each section corresponds to an image projection system. A total overlay error of a first layer deposited on the substrate is determined. For each section, a sectional overlay error is calculated. For each overlap area, in which two or more sections overlap, an average overlay error is calculated. The exposure parameters are adjusted in response to the total overlay error.