AVS 47th International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS2-WeA

Paper PS2-WeA10
Microtrenching, Etching and Sidewall Passivation in Contact Holes and Edge Regions

Wednesday, October 4, 2000, 5:00 pm, Room 311

Session: Feature Evolution
Presenter: B. Abraham-Shrauner, Washington University
Authors: B. Abraham-Shrauner, Washington University
C. Liu, Washington University
Correspondent: Click to Email
Our analytical/numerical models for etching in semiconductor fabrication of integrated circuits are extended to include sidewall passivation and microtreching for contact holes (vias) and edge regions. The models fit oxide etch profiles in SEMS in a CF4/CHF3/Ar plasma.@footnote 1@ Neither grazing scattering of ions from the feature sidewalls@footnote 2@ nor the deviation of the ion trajectories by sidewall charging@footnote 3@ are needed to model mild microtrenching. The model for contact holes includes a new approximate analytic expression for the ion energy flux, Langmuir kinetics for the ions and etching neutrals and the flux for deposition neutrals. The deposition neutrals are modeled by an interpolation between shadowed and isotropic neutrals. The edge region (half trench) model may include enhanced microtreching by scattered ions or distortion of ion trajectories by sidewall charging. The basic shape of the etch profile of the half trench is determined by the ion energy flux and the deposition flux and most of the sidewall is a characteristic of the evolution PDE. @FootnoteText@ @footnote 1@ Etch profile data was furnished by M. J. Buie and J. T. P. Pender of Applied Materials. @footnote 2@ M. Schaepkens and G. S. Oehrlein, Applied Phys. Lett. 72, 1293(1998). @footnote 3@ T. J. Dalton, J. C. Arnold, H. H. Sawin, S. Swan, D. Corliss, J. Electrochem. Soc. 140, 2395 (1993).