Method for calibrating a manufacturing process model

A computer program product containing one or more sequences of machine-readable instructions for calibrating a manufacturing process model, the instructions being adapted to cause one or more processors to perform an operation comprising:

• receiving a measured diffraction pattern of a target structure arising from an illumination of the target structure, the target structure having been produced based on a layout for the target structure and a manufacturing process;
• executing a manufacturing process model to simulate the manufacturing process, the manufacturing process model comprising manufacturing process parameters;
• determining structural information corresponding to the target structure using the manufacturing process model;
• determining a model diffraction pattern using the structural information;
• comparing the model diffraction pattern to the measured diffraction pattern and calculating a merit function based on a result of the comparison;
• generating calibrated manufacturing process parameters based on a result of the merit function;
• and
• calibrating the manufacturing process model using the generated calibrated manufacturing process parameters.

A method of calibrating a structure model comprising:

• measuring, using a scatterometer, a diffraction pattern generated by illuminating a target structure, the target structure being based on a layout;
• simulating the target structure with a structure model, the structure model comprising a 3-D description of the target structure;
• determining a model diffraction pattern using the structure model and the layout;
• comparing the model diffraction pattern to the measured diffraction pattern to generate a comparison result;
• and
• generating calibrated 3-D description of the target structure based on the comparison result;
• and
• calibrating the structure model using the generated calibrated 3-D description.