AVS 45th International Symposium
    Plasma Science and Technology Division Monday Sessions
       Session PS-MoM

Paper PS-MoM4
An Integrated Multi-Scale Modeling Approach to Predicting Ionized PVD Step Coverages

Monday, November 2, 1998, 9:20 am, Room 318/319/320

Session: Feature Evolution
Presenter: D.G. Coronell, Motorola
Authors: D.G. Coronell, Motorola
P.L.G. Ventzek, Motorola
V. Arunachalam, Motorola
C.-L. Liu, Motorola
D.E. Hanson, Los Alamos National Laboratory
J.D. Kress, Los Alamos National Laboratory
A.F. Voter, Los Alamos National Laboratory
Correspondent: Click to Email
Ionized PVD has emerged as a promising technology for inlaid metallization over high aspect ratio features. However, the high cost of process and tool development and the need to forecast the extendibility of ionized PVD processes to smaller features and new materials represent major challenges. Computer-aided process development is an increasingly important means of addressing these challenges. Here we demonstrate how models describing phenomena at several length scales can be integrated to better understand, control, and predict the influence of process settings on ionized PVD step coverages. The relationship between the process variables and the flux of material to the wafer is determined using a detailed equipment scale plasma model.@footnote 1@ The ion flux information is subsequently funneled through a sheath model where the angular and energy distributions of the ions are computed for input to a feature scale model. This is a critical link in the integrated model as it enables a clear understanding of the relationship between equipment level settings and process performance at the feature scale level. An important component of the ionized PVD feature scale model is the description of the interaction of the energetic ions with the feature surface. The ion-surface interaction models were formulated from atomic scale molecular dynamics analyses where the angular and energy-dependent sticking probabilities, sputter yields, and directional characteristics of reflected and sputtered atoms were computed.@footnote 2@ The multi-scale model was applied to ionized Cu PVD where the effects of wafer bias, pressure, target power, and coil power on step coverage are illustrated for various feature geometries. As the feature sizes decrease, a judicial selection of process conditions is required in order to properly engineer the optimal mix of ionization and resputtering according to the model predictions. @FootnoteText@ @footnote 1@ See AVS '98 paper by Ventzek et al. @footnote 2@ See AVS '98 paper by Kress et al.