Kla Tencor Corporation

Kla Corporation

J K Leong

Guoheng Zhao

Michael D Kirk

Christian Wolters

Zhiwei Xu

Kurt Haller

Methods and systems for detecting and classifying defects based on the phase of dark field scattering from a sample are described herein. In some embodiments, throughput is increased by detecting and classifying defects with the same optical system. In one aspect, a defect is classified based on the measured relative phase of scattered light collected from at least two spatially distinct locations in the collection pupil. The phase difference, if any, between the light transmitted through any two spatially distinct locations at the pupil plane is determined from the positions of the interference fringes in the imaging plane. The measured phase difference is indicative of the material composition of the measured sample. In another aspect, an inspection system includes a programmable pupil aperture device configured to sample the pupil at different, programmable locations in the collection pupil.

Methods and systems for optical surface defect material characterization

A inspection system includes an illumination source to generate an illumination beam, focusing elements to direct the illumination beam to a sample, a detector, collection elements configured to direct radiation emanating from the sample to the detector, a detection mode control device to image the sample in two or more detection modes such that the detector generates two or more collection signals based on the two or more detection modes, and a controller. Radiation emanating from the sample includes at least radiation specularly reflected by the sample and radiation scattered by the sample. The controller determines defect scattering characteristics associated with radiation scattered by defects on the sample based on the two or more collection signals. The controller also classifies the one or more particles according to a set of predetermined defect classifications based on the one or more defect scattering characteristics.

Systems and methods for defect material classification

Growing community of inventors

San Jose, CA, United States of America

J K Leong