Fiber-optics Low-coherence Integrated Metrology for In-Situ Non-contact Characterization of Novel Materials and Structures

Abstract

We propose a novel stress metrology technique for measurement of local stress tensor components. Metrology is based on fiber-optic low coherence interferometry and can be applied to study stress not only in semiconductor wafers but in other applications such as displays, solar cells, modern windows.

Combined low-coherence interferometry and spectrally resolved reflectometry for nondestructive characterization of small-diameter high-aspect ratio micro-fabricated and micro-machined structures and multilayer membranes

“…High speed version this technology was recently demonstrated to have potential for in-situ measurements during wafer thinning and wafer grinding process [5]. Low coherence interferometry was also proven a powerful tool for measurement of silicon wafer topography and for metrology of the lateral tensor components of the stress tensor in patterned (product) wafers [6]. Due to the fact that this method does not require access from both sides of the wafer fiber optic low coherence interferometers became popular tools for monitoring wafer thickness during grinding process in failure analysis laboratories [7].…”