Slanted gratings

CD Metrology and Scatterometry:

Slanted Gratings

Critical Dimensions Metrology of Slanted Gratings 

Slanted gratings are used widely in novel applications such as augmented reality waveguides due to their improved optical performance and their ability to selectively suppress certain diffraction orders with respect to the others. However, due to their complex shapes and intricate steps involved in their fabrication process, it is critical to measure their geometrical parameters regularly. Using LabScatter, we can extract geometrical parameters such as pitch, height, width, residual layer thickness, and side-wall angle in a non-destructive manner. The figure below shows signals that are measured from a slanted grating (dots), corresponding fits (solid lines) and the extracted geometrical parameters from the fit.     

(Sample: Courtesy of SCIL Nanoimprint Solutions )