Scanning Electron Microscopy (SEM) is widely used to measure Critical Dimensions (CD) in semiconductor lithography processes. As the size of transistors keeps shrinking, the uncertainty associated with CD-SEM accounts for a fast growing contributor to the entire manufacturing error budget. Capability to predict the metrology results from a CDSEM is highly desirable to quantify the uncertainty of metrology. Simulation has proven to be a valuable means of studying both SEM metrology and photolithography. Monte-Carlo based simulators are generally used to model the detailed image formation process of a CD-SEM, while physics-based photolithography simulations, such as PROLITH™ are commonly used for lithography modeling. However, the high computational cost limits the application of Monte- Carlo based CD-SEM simulations in conjunction with lithography simulation. We present here a compact physical CDSEM simulator which simplifies the image formation process while preserving many essential SEM imaging mechanisms. Several applications of our CD-SEM simulator are presented to demonstrate the predicting capability compared with experiments.

Date Published: 16 September 2014
PDF: 11 pages
Proc. SPIE 9236, Scanning Microscopies 2014, 923618 (16 September 2014); doi: 10.1117/12.2066220

Published in SPIE Proceedings Vol. 9236:
Scanning Microscopies 2014
Michael T. Postek; Dale E. Newbury; S. Frank Platek; Tim K. Maugel, Editor(s)