AVS 52nd International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuM

Paper PS-TuM4
Fluorocarbon Film Deposition in a Gap Structure and Correlation With Trench Sidewall Angle for Fluorocarbon Chemistries in Capacitively Coupled Discharges

Tuesday, November 1, 2005, 9:20 am, Room 304

Session: Plasma Surface Interactions I
Presenter: L. Ling, University of Maryland at College Park
Authors: L. Ling, University of Maryland at College Park
X. Hua, University of Maryland at College Park
B. Orf, University of Maryland at College Park
G.S. Oehrlein, University of Maryland at College Park
E.A. Hudson, Lam Research Corp.
P. Jiang, Texas Instruments
Y. Wang, National Institute of Standards and Technology
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A small gap structure* has been used to study surface chemistry aspects of fluorocarbon (FC) film deposition for FC plasmas produced in a mechanically confined dual-frequency capacitively coupled plasma (CCP) reactor. The small gap structure provides a completely shadowed region without direct ion bombardment, similar to surfaces of sidewalls of trench patterns. On both trench sidewalls and the shadowed surface portions of the small gap structure, very thin fluorocarbon layers are formed by neutral diffusion. The lack of ion bombardment also increases the retention of the chemical structure of the FC film precursors in the deposited films. For C@sub 4@F@sub 8@/Ar, C@sub 4@F@sub 8@/Ar/O@sub 2@ and C@sub 4@F@sub 8@/Ar/N@sub 2@ discharges the deposition rate, composition, and bonding of deposited FC films are determined as a function of processing conditions using ellipsometry and X-ray photoemission spectroscopy. The deposition rate and surface chemistry of FC film deposited in this region depend strongly on discharge chemistry, and atomic force microscopy shows significant nanoscale topography that differs markedly from films produced with simultaneous ion bombardment. The inclinations of feature sidewalls formed for different conditions qualitatively correlate with the deposition rates measured for shadowed surfaces of the gap structure. Results of mass spectrometric investigations are also reported in an attempt to relate the observed compositional differences to radicals produced in the gas phase. @FootnoteText@ * L. Zheng, L. Ling, X. Hua, G. S. Oehrlein, and E. A. Hudson, J. Vac. Sci. Technol. A 23, xxx (2005).