Patent ID: 8381138
Filing Date: 2013-02-19
Classification: G03F

Abstract:
1. A simulation model creating method comprising: forming a resist pattern by transferring a mask pattern on a first substrate with an exposing amount and a focus value being changed; measuring a line width of the resist pattern; calculating a first function which is a polynomial equation including the exposing amount and the focus value as parameters and is fit for measurement results of the line width and calculating a difference value between the measurement results and the approximated value on the first function as a first difference; comparing, by a computer the first difference with a first allowable change range calculated from an irregularity of the exposing amount and an irregularity of the focus value as an allowable change range of the line width and, in the case where a first measurement result of which the first difference becomes larger than the first allowable change range exists in the measurement results, removing the first measurement result and regenerating a first function which is fit for the measurement results after removing the first measurement result; repeating a process of removing the first measurement result and regenerating the first function until the first difference becomes smaller than the first allowable change range; calculating a second function which is a polynomial equation including information on a pattern feature amount which is a feature amount of the pattern as a parameter and is fit for the measurement results of the line width with respect to each pattern feature amount and calculating a difference value between the measurement results and the approximated value on the second function as a second difference with respect to each pattern feature amount; comparing the second difference with a second allowable change range calculated with respect to each pattern feature amount as an allowable change range of the line width with respect to each pattern feature amount and, in the case where a second measurement result of which the second difference becomes larger than the second allowable change range exists in the measurement results, removing the second measurement result and regenerating a second function which is fit for the measurement results after removing the second measurement result; repeating a process of removing the second measurement result and regenerating the second function until the second difference becomes smaller than the second allowable change range; calculating an estimated line width of a pattern performed on a second substrate by performing lithography simulation on the mask by using a first simulation model created based on the measurement results after removing the first measurement result; calculating a difference value between the estimated line width and the measurement results after removing the first measurement result as a third difference; and comparing the third difference with a third allowable change range calculated from an average value and variation of the mask pattern line width as an allowable change range of the estimated line width and, in the case where a third measurement result of which the third difference becomes larger than the third allowable change range exists, removing the third measurement result and creating a second simulation model based on the measurement results after removing the third measurement result.