| AVS 60th International Symposium and Exhibition | |
| Plasma Science and Technology | Wednesday Sessions |
| Session PS-WeM |
| Session: | Fundamentals of Plasma Surface Interactions |
| Presenter: | N.A. Fox-Lyon, University of Maryland, College Park |
| Authors: | N.A. Fox-Lyon, University of Maryland, College Park A.J. Knoll, University of Maryland, College Park J. Franek, West Virginia University V. Demidov, Wright-Patterson Air Force Base M. Koepke, West Virginia University G.S. Oehrlein, University of Maryland, College Park |
| Correspondent: | Click to Email |
Prediction and control of plasma distribution functions in low temperature plasmas are important for control of plasma-materials interactions. Reactive impurity additions to inert plasmas are important due to their large effects on both plasma properties and role in plasma-surface interactions. H2 and/or D2 added to Ar is an increasingly large topic of interest. The addition of small amounts of H2/D2 to Ar cause a change from physical to chemical sputtering of etching surfaces. Sode et al. have shown that small additions of H2 to Ar cause unpredicted distrib utions of ion composition and a large loss in plasma density [1]. We investigate the effect that addition of small amounts of H2/D2 has on the ion compositions and energy distributions, along with effects on the plasma electrical properties and neutral and metastable species. D2 addition to Ar plasma causes a faster transition to predominant ArD+ ions than H2 addition causes transition to predominantly ArH+ ions. We also report on the effect H2/D2 added to Ar plasma has on the Ar metastable concentration. We find that, like the effect on plasma density, the metastable concentration decreases rapidly with the introduction of H2 impurities. We find measureable differences for these effects when using D2 impurity instead of H2 impurity. The effect of these changes to plasma properties by H2/D2 impurity addition is also reflected in the plasma material interactions with hydrocarbon films. While ion mass falls gradually with addition, etch rate and modification change drastically. Direct plasma and neutral-based etching experiments were performed for different chemistries to separate the effects of ion composition/mass and reactive neutrals generated in the plasma. The authors gratefully acknowledge financial support from US Department of Energy (DE-SC0001939).
[1] Sode et al. J. Appl. Phys. 113, 093304 (2013)