Paper PS+SS-ThA3
CF and CF₂ Contributions to Plasma-Enhanced Chemical Vapor Deposition of Fluorocarbon Films in C_xF_y Systems

Thursday, November 3, 2011, 2:40 pm, Room 202

Inductively coupled fluorocarbon (FC) plasmas produced from C_xF_y (x,y ≥ 1) precursors are widely employed in industrial processes ranging from circuitry fabrication to preparation of low-k optical coatings. The utility of the plasma system is largely dictated by the y/x ratio, specifically in that precursors with lower ratios tend to more efficiently deposit FC films. Film growth is thought to be related to the behavior of radical species within the plasma, such as CF and CF₂. We report here on gas-phase behavior of these radicals in FC plasma systems with precursor y/x ratios ≤ 4, including relative gas-phase concentrations and kinetics and subsequent contributions to Si wafer processing. Our imaging of radicals interacting with surfaces (IRIS) experiment reveals that the propensity for scatter of CF and CF₂ declines dramatically with decreases in precursor y/x ratio. Similarly, with decreasing y/x ratios, we observe increases in FC film surface energies, suggesting that avenues to tailor specific film properties are feasible. High-resolution x-ray photoelectron spectra and surface sum frequency vibrational spectra which corroborate the relationship between the choice of precursor and characteristics of deposited FC films will also be discussed. Ultimately, this work aims to establish a connection between species behavior near surfaces and resulting film properties during FC plasma processing.