<title>Measurement of the nanometric deformation field in metallic microbars with microscopical ESPI</title>

Abstract

The optimization of microcomponents in nanotechnology requires the knowledge of the mechanical properties of the micromaterials used. These properties cannot simply be inferred from tests with macroscopic specimens. Therefore, experiments with microsamples must be performed. One of the most serious problems hereby is the measurement of the occurring deformation. Various methods have been sued so far, all suffering from the limitation of providing the deformation in one single point only rather than the whole deformation field. Electronic speckle pattern interferometry (ESPI) is an established method for measuring deformation fields in macroscopic objects. In this paper we show how the problems in applying ESPI to microscopical objects can be solved. We present an unusual fringe analysis technique which requires no phase demodulation. It allows to obtain phase maps with a quality that was hitherto only known from holography. Our deformation measurements on metallic microbars agreed to within 10nm with the results form the least squares template matching method and from finite element calculations. One advantage of being able to measure the whole deformation field is that the occurrence of local plastification can be detected, as our experiments suggest.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.