3D multi-layered film thickness profile measurements based on photometric type imaging ellipsometry

Abstract

In this investigation, we describe an imaging ellipsometric method to measure 3D thickness profiles of a multi-layered film structure. Opposed to traditional imaging ellipsometry to improve the spatial resolution using high magnification objectives, we adopt a low magnification imaging lens system approximately 1x to extend the measuring area. In addition, photometric type imaging ellipsometry is implemented to reduce the acquisition time and memory usage. Before film thickness measurements, the incident angle of incoming light and polarization axes of the optical components were calibrated by hardware and software. Several specimens were successfully measured by the photometric type imaging ellipsometer and the repeatability for 15 consecutive measurements was less than 0.5 nm.