M. Backshall, N. Davey, K. S. Robinson, R.Champaneria

VG Scientific, The Birches Industrial Estate, Imberhorne Lane, East Grinstead, West Sussex RH19 1TL England

There is an increasing need for XPS analysis of large samples, particularly in the semiconductor industry where 8 inch wafers are now common. One common use of XPS is the measurement of film thickness by varying the take-off angle of the photoelectrons and consequently the analysis depth. However, with large samples it can be difficult to tilt the sample to enable grazing take-off angle spectra to be acquired from any point on the sample.

In this paper we describe and present results from an instrument with two XPS analysers positioned at normal and grazing take-off angles which allows normal and surface sensitive XPS spectra to be acquired without moving the sample. This concept is taken a stage further on our latest instrument incorporating a 'Radian Lens' which acquires surface and subsurface information without tilting the sample. For both instruments, the analysis area is defined using a focussed monochromatic X-ray source and this also enables analysis of small features at the two take-off angles without any change in the size, shape or angle of incidence of the monochromator spot.