Arie Jeffrey Den Boef,Maurits Van Der Schaar,Andreas Fuchs,Martyn John Coogans,Kaustuve Bhattacharyya,Stephen Peter Morgan,Michael Kubis
申请号：
US13181932
公开号：
US08908147B2
申请日:
2011.07.13
申请国别(地区):
US
年份:
2014
代理人:
摘要：
A method of determining an overlay error. Measuring an overlay target having process-induced asymmetry. Constructing a model of the target. Modifying the model, e.g., by moving one of the structures to compensate for the asymmetry. Calculating an asymmetry-induced overlay error using the modified model. Determining an overlay error in a production target by subtracting the asymmetry-induced overlay error from a measured overlay error. In one example, the model is modified by varying asymmetry p(n′), p(n″) and the calculating an asymmetry-induced overlay error is repeated for a plurality of scatterometer measurement recipes and the step of determining an overlay error in a production target uses the calculated asymmetry-induced overlay errors to select an optimum scatterometer measurement recipe used to measure the production target.
