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

Paper PS-MoM3
Feature Evolution Simulations of Silicon Trenches

Monday, November 2, 1998, 9:00 am, Room 318/319/320

Session: Feature Evolution
Presenter: H.H. Hwang, Thermosciences Institute
Authors: H.H. Hwang, Thermosciences Institute
D. Bose, Thermosciences Institute
T.R. Govindan, NASA Ames Research Center
M. Meyyappan, NASA Ames Research Center
Correspondent: Click to Email
Understanding how an evolving microfeature is affected by process parameters, such as those that are controlled by knobs on the reactor panel, is of great interest. This is possible only if the feature level model is coupled to a reactor level model. We have developed a level set theory based profile evolution model to simulate the moving gas-solid interface between the semiconductor and plasma. This approach is an alternative to string algorithms which suffer from looping problems and are not easy to implement in three dimensions. Our model includes both the isotropic and anisotropic components of etching, and considers reemission of neutrals and ions inside the trenches. We have also developed a comprehensive reactor model which can provide the necessary input parameters for the level set simulation. The multidimensional reactor analysis code solves the complete set of Navier-Stokes equations for plasma transport, neutral species dynamics, gas flow, heat transfer, and Maxwell's equations for power deposition from an external source in a coupled manner to provide concentrations, fluxes, and energies of various species as a function of process parameters. We have validated the reactor model against available experimental data for N@sub 2@ plasmas (10 mTorr, 100 sccm) in a 300 mm etch ICP reactor. The current analysis shows that the model reproduces plasma properties, such as electron density, temperature, and their variations, with reasonable accuracy. We will present results from the feature profile simulation in pure chlorine plasmas in an ICP reactor at 1-10 mTorr and 20-100 sccm, based on the calculations generated from the reactor model. Comparisons to experimental data will also be presented. Support for Bose and Hwang provided by NASA contract NAS2-14031 to Eloret.