AVS 45th International Symposium
    Plasma Science and Technology Division Tuesday Sessions
       Session PS1-TuM

Paper PS1-TuM3
Surface Composition and Reactivities of Fluorocarbon Radicals from Pulsed Fluorocarbon Plasmas

Tuesday, November 3, 1998, 9:00 am, Room 314/315

Session: Pulsed Plasmas
Presenter: E.R. Fisher, Colorado State University
Authors: N.M. Mackie, Colorado State University
J. Bard, Butler University
N.E. Capps, Colorado State University
E.R. Fisher, Colorado State University
Correspondent: Click to Email
Pulsed fluorocarbon plasmas are becoming an increasingly popular method to deposit materials with high fluorine content for a variety of thin film applications and to reduce the adverse charging effects during dry etching. Despite the enormous bod y of work on continuous wave (CW) fluorocarbon plasmas, the underlying deposition and etching mechanisms in pulsed and CW plasmas are still controversial. Pulsed hexafluoropropylene oxide (HFPO) plasmas have been postulated to deposit films from surface reactions of CF@sub 2@ radicals even though the sticking coefficient of CF@sub 2@ is known to be low. We have performed a critical comparison of fluorocarbon films deposited from variable duty cycle pulsed and equivalently powered CW HFPO plasmas. We have determined the duty cycle dependence of CF@sub 2@ reactivities and relative gas phase densities from CW and pulsed HFPO plasmas using our Imaging of Radicals Interacting with Surfaces (IRIS) method, which combines spatially resolved laser-induced fluore scence (LIF) with molecular beam techniques.. Preliminary results show that CF@sub 2@ radicals indeed have a low reactivity in a 5% pulsed HFPO plasma with R = -0.1 ± 0.07 and that there is some surface production of CF@sub 2@ during pulsed plasma processing. In addition, time resolved optical emision spectroscopy (OES) has been used to track excited state atoms and radicals throughout the pulse cycle. Insights into the deposition mechanism of HFPO pulsed and CW plasmas will be discussed.