Contour Metrology using Critical Dimension Atomic Force Microscopy

Published

December 15, 2016

Author(s)

Ndubuisi G. Orji, Ronald G. Dixson, Boon Ping Ng, Andras Vladar, Michael T. Postek

Abstract

The critical dimension atomic force microscope (CD-AFM) has been proposed as an instrument for contour measurement and verification – since its capabilities are complementary to the widely used scanning electron microscope (SEM). Although data from CD-AFM are three dimensional in structure, the planar two-dimensional data required for contour metrology is not easily extracted from CD-AFM data. This is largely due to the limitations of the CD-AFM method for controlling the tip position and scanning, in which the relevant sidewall data is only obtained in one lateral axis. In order to use CD-AFM for contour metrology, the extracted profiles must include actual sidewall data from both lateral axes. Using two images acquired from orthogonal scan directions, profile extraction, and a method to combine those profiles, a technique for obtaining contours with the CD-AFM is developed. The main sources of error for this technique are described. The contours derived from CD-AFM were compared with those obtained using the SEM. Our results show that CD-AFM has the potential to make important contributions to semiconductor contour metrology.

Citation

Journal of Micro/Nanolithography, MEMS, and MOEMS

Volume

15

Issue

4

Pub Type

Journals

Download Paper

https://doi.org/10.1117/1.JMM.15.4.044006

Keywords

contour metrology, critical dimension atomic force microscope, scanning electron microscope, profile extraction.

Citation

Orji, N. , Dixson, R. , , B. , Vladar, A. and Postek, M. (2016), Contour Metrology using Critical Dimension Atomic Force Microscopy, Journal of Micro/Nanolithography, MEMS, and MOEMS, [online], https://doi.org/10.1117/1.JMM.15.4.044006 (Accessed October 10, 2025)