Ion induced chemical damage to surfaces : an investigation by X-ray photoelectron spectroscopy

The current upsurge in the use of ion beam techniques in the fabrication of microelectronic devices has meant a greater understanding of the processes involved. The physical aspects of this technique have been, and continue to be, widely researched. However, until recently, little work had been undertaken into the chemical aspects of sputtering. The commonly used theories explaining preferential and chemical sputtering are described together with an overview of the main theories describing physical sputtering. As an extension to the theories covering chemical aspects of sputtering, an appendix is included which covers the commonly available references, up to the end of 1983, which have included chemical changes associated with sputtering. The aim of the project was to extend the range of materials which had been examined, to measure the degree of chemical damage induced by sputtering. As such, a range of Group I and Group IV salts were studied and the results presented herein are discussed with reference to possible mechanisms of dissociation. A non-destructive surface sensitive analytical technique was essential to this study and the method chosen was X-ray photoelectron spectroscopy, of which some of the background theory is also included.