title: Direct measurement of beam size in a spectroscopic ellipsometry setup.
abstract: Spectroscopic ellipsometry signals used in thin film analysis are dependent on the beam probe size. In this work, we report a technique to determine the beam size that uses the existing detection facilities in a spectroscopic ellipsometry setup without the need to rearrange the optical components. The intensity signal recorded with the technique comprises a coupled boundary diffraction and knife edge wave that can be isolated using nonlinear fitting. This then permitted an accurate measurement of the beam size with the stronger knife edge component. The technique has the added advantage of picking up chromatic aberration in the probing lens which may be a factor in ellipsometry measurement.
authors.affiliation: Department of Electrical and Computer Engineering, National University of Singapore, Singapore.
authors.forename: Arthur
authors.initials: A
authors.lastname: Tay
authors.forename: Tuck Wah
authors.initials: TW
authors.lastname: Ng
authors.forename: Yuheng
authors.initials: Y
authors.lastname: Wang
authors.forename: Shao
authors.initials: S
authors.lastname: Zhao