System and method for use in high spatial resolution ellipsometry

An optical module configured as microscope attachment for providing ellipsometry measurement of a sample, the module comprises:

• an illumination channel connectable to a light source and comprising at least a polarization modulation unit, a collection channel comprising a polarization analyzer unit and a detector array, and a control unit comprising a memory utility and at least one processor utility comprising an angle calibration module;
• the illumination channel is configured to provide collimated illumination directed along a first general optical axis at an objective lens of the microscope such that said first optical axis is parallel with respect to main optical axis of the objective lens;
• the collection channel is configured for collecting light from said objective lens along a second general optical axis being parallel to said main optical axis, transmitting said collected light through said polarization analyzer unit and collecting said light on the detector array being located at a Fourier conjugate optical plane with respect to sample being inspected, thereby providing image data associated with high spatial resolution ellipsometry measurement;
• wherein said angle calibration module being configured for selectively carrying out calibration of collected angular data of said image data by:
• retrieving reference data about at least two reference sample, said reference data being indicative of complex refractive index of the reference samples;
• generating system command requesting for collection of ellipsometry data of said at least two reference samples using the system;
• processing generated image data pieces corresponding with said at least two reference samples in accordance with said reference data, said processing comprises simultaneously determining for each measurement point corresponding to an incident angle, system parameters and corresponding angle of incidence in accordance with corresponding parameters of the reference sample to thereby generate calibration data, and storing said generated calibration data in a memory utility;
• the control unit is configured for receiving data from the detector array and for processing said data in accordance with said system calibration data for assigning data on incident angle of light components with corresponding data points of the output image data.

A software product embedded in a non-transitory computer readable medium and comprising computer readable instructions which, when executed by a computer, cause the computer to:

• obtaining reference data on at least two reference samples from one or more selected data sources, said data being indicative of complex refractive index of the reference samples;
• generating operation instructions for operating an optical ellipsometry measurement system providing ellipsometric data for a plurality of angular direction of said at least two reference samples, and receive input data having a plurality of data pieces, each associated with unknown angular position;
• processing the input data in accordance with said reference data for determining calibration data for said optical ellipsometry system, said processing comprising:
• for each data piece corresponding to an unknown angular position, determining simultaneously system parameters and corresponding angle of incidence in accordance with corresponding parameters of the reference sample to determine calibration data.