Distributions of plasma parameters, such as electron temperature and electr
on density have been studied for large-volume processing. In terms of preci
se study of large-volume plasma, ion-species distributions in plasma should
be measured as well as those of plasma parameters. However, no method to m
easure the spatial distributions of ion species has been developed so far.
In this study, we construct a new apparatus to measure the ion-species dist
ribution by using a quadrupole mass spectrometer, which can be moved in vac
uum perpendicularly to the beam extraction. Furthermore, we propose a new m
ethod to generate uniform plasma by introducing gas in pulse and generate p
ulsed plasma correspondently with the gas introduction. The results suggest
that the ion-species distributions are not consistent with the electron-de
nsity distribution and spatial distributions of ion species can be improved
by introducing gas in pulse and generating pulsed plasma. For further stud
y towards the next-generation semiconductor fabrication, the ion-species di
stributions in large-volume plasma should be taken into account as well as
those of the other plasma parameters. (C) 2001 Elsevier Science B.V. All ri
ghts reserved.