Development of reference materials for the investigation of local mechanical properties at the nanoscale

Abstract

At present, local mechanical properties can be measured not only for macroscopic objects but also for nano-objects and thin films with dimensions of only a few tens of nanometers. For these purposes, special indentation devices can be used. In past decades, many special data measurement and processing methods for thin film characterization have been developed. In addition, the method is no longer restricted to materials science but now also has a wide range of applications for biological problems in which the hardness/modulus values are quite different from those in materials science for which the method was originally designed. Data interpretation in the field of metrology is not so straightforward and care is required in dealing with quantitative results, especially if dealing with very soft samples. Therefore, it is necessary to use reference samples that would enable the comparison of different instruments and the validation of the applied methods. In this contribution, we present the results of our effort on preparing and testing thin film-based reference materials prepared using plasma technologies. We describe a deposition procedure that allows us to produce samples with a large range of hardness and modulus values. From these, we choose a very soft but stable sample that is then further tested to verify its suitability as a reference sample. The major issues discussed in this article are the repeatability of the deposition process, time stability, and homogeneity.

AFM characterization of nanocomposite SAMPLES

“…The samples were produced using plasma enhanced chemical vapor deposition from hexamethyldisiloxane (HMDSO) and oxygen. The details of the deposition process are described in [6]. A capacitive radio frequency discharge at 13.56 MHz was generated in a parallel plate reactor.…”

“…Deposition under dusty plasma condition can be used for depositing nanocomposite thin films, with many successful technological applications. Varying the deposition conditions allows to obtain films with different properties, such as elasticity or hydrophobicity [1][2][3][4][5][6].…”

Nanometrología: Impacto en los sistemas de producción

“…Un avance significativo es la aplicación de técnicas para medir las propiedades mecánicas a escala nanométrica, como la nanoindentación, la cual es implementada en ciencias biológicas, de los materiales, entre otras [32] . Esta técnica tiene una alta "reproducibilidad, que permite el análisis de muestras pequeñas, delgadas y heterogéneas" y de la superficie de las mismas [33]; Xia y colaboradores hacen referencia a la utilidad de este ensayo para la medición de las propiedades mecánicas en menor escala, como: la dureza y rugosidad de superficie del material, siendo esta última una propiedad que afecta directamente la dureza, dado que las mediciones dependerán del primer punto de contacto entre las superficies, por lo que se requieren herramientas que proporcionen la mayor exactitud posible [34].…”

Atomic Force Microscopy Measurements of the Area Function of a Sphero-Conical Tip

“…Highly elastic transparent thin films with low plasticity that can maintain structural integrity even under severe strain conditions are important for development of flexible optoelectronic devices [6,7]. A conical tip with a large radius is very well suited to study the elastic behavior with little influence from plasticity.…”