Paraboloidal ellipsometer with accurate retardance and latitude
Journal
Proceedings of SPIE - The International Society for Optical Engineering
Journal Volume
4400
Pages
70-81
Date Issued
2001
Author(s)
Abstract
A newly developed miniature phase-modulation variable angle Ellipsometer named PEARL was detailed. PEARL is an acronym of Paraboloidal Ellipsometer with Accurate Retardance and Latitude. This newly developed system was designed by using a diamond turned axis-symmetric paraboloidal metallic mirror and a concave spherical mirror to accurately control the incident angle of the probing light beam. The penta prism carried by a precision servomotor was designed to change the incident light beam. Coupling the 0.4mm accuracy of today's servomotor, the extreme accurate figure achieved by the diamond turning machine, and the newly invented metallic mirror set, PEARL achieved the goals of miniaturization and with accurate incident angle control. The built-in self-calibration system of PEARL, which provide us with an opportunity to eliminate the expensive and hard-to-maintain standard specimen was also discussed. Modification to the paraboloidal mirror and the spherical mirror in order to resolve the non-unique probing point problem in in-situ process control of semiconductor processing and flying height measurement of magnetic disk drives will also be detailed.
Type
conference paper