Linewidth Measurement Intercomparison on a BESOI Sample

Published

June 1, 2000

Author(s)

John S. Villarrubia, Andras Vladar, J R. Lowney, Michael T. Postek, Richard A. Allen, Michael W. Cresswell, Rathindra Ghoshtagore

Abstract

The effect of the instrument on the measurement must be known in order to generate an accurate linewidth measurement. Although instrument models exist for a variety of techniques, how does one assess the accuracy of these models? Intercomparisons between techniques which rely upon fundamentally different measurement physics can play an important role in model verification. We report here such an intercomparison. The average linewidth of a test pattern on a BESOI (Bonded and Etched-back Silicon on Insulator) sample, which is single crystal silicon with a buried insulating oxide, was measured using scanning electron microscopy (SEM) and electrical critical dimension (ECD) techniques. The higher conductivity of the BESOI sample compared to a previously measured SIMOX (another silicon on insulator technology) sample reduced the ECD uncertainty. Unexpected features in the SEM image were fit by modeling the cross sectional geometry of the line as a skewed trapezoid with deviations of a few tenths of a degree from the expected 90 angles. The SEM and ECD results differed by 54 nm. This is larger than can be accounted for by known sources of experimental uncertainty.

Proceedings Title

Proceedings of SPIE, Metrology, Inspection, and Process Control for Microlithography XIV, Neal T. Sullivan, Editor

Volume

3998

Conference Dates

February 28, 2000

Conference Location

Santa Clara, CA

Conference Title

SEM Methods for CD Metrology I

Pub Type

Conferences

Keywords

critical dimension, electrical critical dimension, linewidth metrology, scanning electron microscopy

Citation

Villarrubia, J. , Vladar, A. , Lowney, J. , Postek, M. , Allen, R. , Cresswell, M. and Ghoshtagore, R. (2000), Linewidth Measurement Intercomparison on a BESOI Sample, Proceedings of SPIE, Metrology, Inspection, and Process Control for Microlithography XIV, Neal T. Sullivan, Editor, Santa Clara, CA (Accessed October 10, 2025)