Paper PS2-WeA7
Probing CF and CF₂ Surface Reactivities in Inductively-Coupled Fluorocarbon Plasmas

Wednesday, October 31, 2012, 4:00 pm, Room 25

Inductively-coupled fluorocarbon plasmas (FCPs) provide a wide range of potential applications from circuitry fabrication to preparation of optical coatings. In these systems, etching and deposition processes often occur simultaneously, with the net effect of surface processing dictated by the balance between the two phenomena. The behavior of CF_x (x=1,2) species in particular provide insight into these competing processes and allow for elucidation of the mechanisms of FCP processing. We have examined CF_x radical scatter coefficients (S) at the gas-surface interface for a range of FCPs during plasma-enhanced chemical vapor deposition (PECVD). Our imaging of radicals interacting with surfaces (IRIS) experiments reveal that CF and CF₂ species scatter from surfaces with a high probability in each of the systems investigated. These high scatter values are related to the ion energies of nascent plasma species, as measured by mass spectrometry. Highly energetic ions ablate fluorocarbon passivation layers to extricate CF_x units. The presence of vibrationally hot CF(²Δ) radicals correlates directly with increasing scatter values for CF(²Π), suggesting that internal energy transfer at surfaces is another important factor contributing to the observed S. The connection between interfacial interactions and the PECVD-deposited film is a critical component to consider for improved plasma applications and for designing specificity in fluorocarbon film properties. Ultimately, by controlling the parameters associated with our plasma systems, we can create tailored films with specific compositions and surface energies. The efforts recounted here offer additional insight into the fundamental plasma processes so crucial for advancement of plasma technology.