AVS2011 Session EW-TuL: Exhibitor Technology Spotlight

The application potential of graphene is currently being extensively explored by the materials science community. Its utility as a transparent conductive electrode for the microelectronics industry is already being exploited. More recent progress has demonstrated how the unique combination of electronic, chemical, and structural properties of graphene will have a significant impact on the development of next-generation thin film transistors. Additional applications of graphene to molecular sensors are underway. In all stages of development there is a critical requirement for materials characterization and analysis: from the initial research stages through to testing of the finished devices. Because most materials need to be analyzed for compositional homogeneity both across the surface and through the thickness of a given sample, a complementary approach involving several techniques is often required.

In this presentation we will discuss how a multi-technique approach using Raman spectroscopy and XPS can address the problems associated with the analysis of ultra thin film materials. Raman microscopy is a vibrational technique that is very sensitive to small changes in a molecule’s geometric structure and its environment. This sensitivity allows Raman to be used as a probe for a number of properties important to a specific graphene sample. These properties include, but are not limited to layer thickness, the presence or absence of defects, and local strain. XPS enables complete characterization of thin graphene films with respect to chemical modification, in addition to the chemical interaction between the film and the substrate. The combined XPS/Raman measurement approach will be applied to graphene produced by both exfoliation and CVD methods, providing a full comparison of the chemical and structural information offered by each technique.

Over the last several years multiple methods have developed for the depth profile analysis of organic materials using a variety of different polyatomic species as the sputtering ion. It has also become clear that different classes of polymers require quite different sputtering parameters to be effectively profiled with no loss of chemical information. In this presentation we discuss a variety of approaches that have developed in order to effectively sputter profile a wide range of materials. These approaches utilize differences in ion beam energy, impact angle and sample temperature in order to achieve an effective sputter profile.