AVS 46th International Symposium
    Applied Surface Science Division Thursday Sessions
       Session AS-ThM

Paper AS-ThM10
Diffusion of Large Molecules on Metallic Surfaces using TOFSIMS

Thursday, October 28, 1999, 11:20 am, Room 6A

Session: Real World Surface Analysis
Presenter: R. Avci, Montana State University
Authors: R. Avci, Montana State University
S.E. Maccagnano, Montana State University
G.L. Gresham, Idaho National Engineering and Environmental Laboratory
G.S. Groenewold, Idaho National Engineering and Environmental Laboratory
Correspondent: Click to Email
The environmental contamination of clean surfaces creates challenging problems in practical surface analysis. In most cases the contamination is caused by a contact between a dirty and a clean surface and the subsequent diffusion of the contaminant over the clean surface. In this presentation a semi-quantitative study of the diffusion process of large molecules such as polydimethylsiloxane and tributyl phosphate on metallic surfaces will be presented. Using imaging time-of-flight secondary ion mass spectroscopy (ToFSIMS) we have monitored the diffusion of these molecules by first absorbing them on the surface of a fiber such as linen and nylon and then placing the fiber in contact with a metallic surface such as a gold-coated silicon wafer. ToFSIMS spectra are taken as (a) a function of distance from the contact point and (b) a function of time from moment of contact to determine the diffusion properties of these molecules on the surface. Our preliminary observations show that these molecules rapidly diffuse away from the contact point on the surface of the metal.