AVS 53rd International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS2-TuA

Paper PS2-TuA4
Scaling of Dual Frequency Capacitively Coupled Plasma Etching Tools Above 100 MHz*

Tuesday, November 14, 2006, 3:00 pm, Room 2011

Session: Etch for Advanced Interconnect II
Presenter: Y. Yang, Iowa State University
Authors: Y. Yang, Iowa State University
M.J. Kushner, Iowa State University
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Capacitively coupled dual frequency reactive ion etching reactors allow, in principle, independent control of the ion flux and ion bombardment energy which is important for obtaining high selectivity. There is great interest in extending the high frequency to values approaching or exceeding 100 MHz to increase the proportion of power dissipated in electron heating while lowering the electron temperature. These trends are believed to produce more favorable dissociation pathways in, for example, fluorocarbon etching. In this talk, results will be discussed from a computational investigation of dual frequency RIE reactors for high frequencies exceeding 100 MHz. This study was performed with a two-dimensional hybrid-fluid model. To properly address the coupling between the electric field and electron transport under high frequency conditions, a fully implicit electron transport algorithm was developed. Spatially dependent electron energy distributions generated by a Monte Carlo simulation, which properly captures the high frequency heating, provide excitation rates. Results from studies in rare gases and fluorocarbon gas mixtures (e.g., Ar/C@sub 4@F@sub 8@/O@sub 2@) will be presented as a function of the high frequency while keeping power constant. Assessments of the change in dissociation pathways, radical fluxes; and ion energy and angular distributions to the substrate will be presented. @FootnoteText@ *Work supported by the Semiconductor Research Corp. and the National Science Foundation.