Optimization Method and a Lithographic Cell

A method comprising:

• carrying out a first manufacture step having at least one first variable, the first manufacture step resulting in a first intermediate feature;
• measuring a first characteristic of the first intermediate feature;
• carrying out a second manufacture step having at least one second variable, the second manufacture step resulting in a second intermediate feature;
• measuring a second characteristic of the second intermediate feature;
• modeling a final characteristic of a final feature based on the first and second variables and at least one of the first and second characteristics;
• measuring the final characteristic;
• comparing the modeled final characteristic and the measured final characteristic;
• updating the model;
• modifying at least one of the first variable and the second variable to optimize the final characteristic;
• and
• carrying out the first and second manufacture steps using the modified at least one of first and second variables.

A lithographic cell comprising:

• a lithographic apparatus configured to project a pattern from a patterning device onto a substrate;
• a measuring system configured to measure a first characteristic of the substrate, measured after a first manufacture step, a second characteristic of the substrate, measured after a second manufacture step, and a final characteristic of the substrate;
• and
• a controller configured to:
• model a final characteristic of a feature based on at least one of the first characteristic and the second characteristic, compare the measured final characteristic and modeled final characteristic, update the model and determine an optimum variable for at least one of the first and second manufacture steps based on the updated model.

A method comprising:

• manufacturing a plurality of first features and second features, the second features and the first features alternating, each the second feature separated from a first feature by a first space and each the first feature separated from a second feature by a second space, the first features having a critical dimension L1, the second features having a critical dimension L2, the first space having a critical dimension S1 and the second space having a critical dimension S2, wherein L1, L2, S1 and S2 being characteristics and the manufacturing process having a variable which affects the characteristics of the features and the spaces;
• measuring at least two characteristics V1, V2;
• optimizing the variable by minimizing a relationship between two the characteristics multiplied by a weighting factor a;
• and
• manufacturing a plurality of first and second features using the optimized variable,
• wherein the weighting factor a is determined by the variance of V1 and V2.