AVS 45th International Symposium
    Plasma Science and Technology Division Wednesday Sessions
       Session PS-WeM

Paper PS-WeM6
Modeling of Charging Damage during Dielectric Deposition in High-Density Plasmas

Wednesday, November 4, 1998, 10:00 am, Room 318/319/320

Session: Plasma Damage
Presenter: K.P. Giapis, California Institute of Technology
Authors: G.S. Hwang, California Institute of Technology
K.P. Giapis, California Institute of Technology
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The mechanism of charging up of interconnect metal lines during interlevel dielectric (ILD) deposition in high-density plasmas is investigated by detailed and self-consistent Monte Carlo simulations of pattern-dependent charging.@footnote 1@ The results suggest that the initial conformality of the ILD film plays a crucial role in metal line charging up and the subsequent degradation to the buried gate oxide to which the metal line is connected. Line charging occurs when the top dielectric is thick enough to prevent tunneling currents while the sidewall dielectric thickness still allows tunneling currents to flow to the metal line; the differential charging of the sidewalls, which induces the latter currents, is caused by electron shading. The simulations include a treatment of charge dissipation along the surface of the dielectric;@footnote 2@ surface currents can significantly decrease the cumulative charging damage when facile at small surface potential gradients. Charging damage during plasma-assisted ILD deposition could become a problem more serious than that occurring during plasma etching and is expected to pose additional requirements to low-k dielectrics currently sought to replace SiO@sub 2@. However, under the assumptions considered, a dramatic reduction in charging damage can be accomplished by depositing a more conformal ILD film around the metal line and/or by increasing the ability of the film surface to dissipate charge. @FootnoteText@ @footnote 1@ G. S. Hwang and K. P. Giapis, J. Appl. Phys., Vol. 84, to appear on July 1, 1998. @footnote 2@ G. S. Hwang and K. P. Giapis, Appl. Phys. Lett., Vol. 71, 458 (1997).