Paper PS+SS-TuA12
Extending the Legacy of Harold Winters: Probing the Energetics and Plasma-Surface Interface of Halogenated Plasmas

Tuesday, October 31, 2017, 6:00 pm, Room Ballroom B

In the arena of halocarbon plasma chemistry, Harold Winters and co-workers performed pioneering work by extensively exploring plasma-assisted etching of semiconductor materials using a range of halogenated systems. For example, Coburn and Winters explored the role of energetic ions in plasma-assisted etching in silicon-fluorine systems, studying the dynamic interplay between physical and chemical sputtering. This work has inspired several decades of work on halogenated plasma systems, including further elucidation of the role of ions and other energetic species within plasmas. In this work, energy partitioning for molecules formed from fluorinated plasma systems has been measured using laser-induced fluorescence, optical emission and broadband absorption spectroscopies. Focusing on two fluorinated species, SiF in SiF₄ plasmas and CF_x in C_xF_y fluorocarbon plasmas, we find that small molecules in these systems exhibit extremely high electronic excited state vibrational temperatures, T_V, relative to rotational temperatures, T_R. This suggests that vibrational modes are preferentially excited over other degrees of freedom. Using the imaging of radicals interacting with surfaces (IRIS) technique, surface scattering coefficients measured for each radical show a strong correlation with the associated T_V, with little dependence upon T_Ror translational temperatures. This presentation will focus on plasma deposition and etching systems where understanding the relationship between the gas-phase and the resulting surface properties allows for deeper insight into creating advanced functional materials for a range of applications. Specific examples will include fluorocarbon film formation as well as production and modification of multidimensional materials.