A simple method to prepare carbon substrates for RBS analysis

Abstract

We have investigated the possibility of forming 2 μm thick low Z (carbon, Z = 6) layers on Si wafers via simple and conventional semiconductor processing techniques. These carbon substrates were prepared by spinning a layer of photoresist (Shipley AZ1350J or 1400-33) onto Si substrates and then heating at temperatures of up to 900°C. The resulting carbon layer is sufficiently thick to shift the RBS signal due to the Si to energies below that corresponding to C on the surface. As an example we show the use of these carbon film in the investigation of the SiAu system. In this paper, we present a discussion on the preparation of the carbon substrate and application of these substrates in the investigation of oxidation of the AuSi system and other systems commonly encountered in thin film investigation. The objective of this investigation is to show that very simple techniques commonly available in semiconductor laboratories can be used to fabricate carbon substrates suitable for backscattering analysis.