Abstract
Silicon wafers that are fabricated by the Czochralski tech- nique contain pyramidal pits, which are referred to in more general terms as crystal-originated particles (COPs). Because wafer inspection sys- tems now benefit from the predictability of scattering from particles of known size, shape, and composition, it is of interest to achieve the same level of predictability for surface breaking defects such as pits. A model, valid for s-polarization and a high incidence angle, is based on the Fraunhoffer approximation for the diffraction from a square aperture, and is enhanced by an empirically derived term that accounts for the scatter component attributed to facets. Measurements and the model show that (using the prescribed optics configuration) a characteristic peak occurs between 20 and 45 deg in the forward scatter region, which increases in magnitude and moves forward with increasing pit size. This kind of infor- mation can be used to improve an instrument's ability to distinguish be- tween surface particles and COPs by strategically positioning detectors accordingly. Furthermore, the model can be used as a check against numerical models that are designed to predict scatter from pyramidal pits that are of size equal to a wavelength or much smaller. © 2002 Society of
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
