SIMULATIONS OF BCL3 CL-2/AR PLASMAS WITH COMPARISONS TO DIAGNOSTIC DATA/

A reaction mechanism is reported that describes BCl3/CI2/Ar plasmas us ed in the etching of metal lines in microelectronics fabrication proce sses. Although many of the fundamental electron-impact cross sections for this system are not well known, a reasonable set of reaction paths and rate coefficients has been derived to describe low-pressure react ors with high plasma density. The reaction mechanism describes 59 poss ible gas-phase events and 18 plasma-surface interactions. A well-mixed reactor model is used to develop the reaction set and to test it agai nst absolute experimental measurements of electron and Cl- densities, as well as relative measurements of BCl and Cl radicals in an inductiv ely coupled research reactor. The experimental data cover a wide range of operating conditions and gas mixtures. The model provides quantita tive agreement with measurements over the whole range of conditions an d diagnostics, capturing most of the observed trends. in addition, the model predicts relative ion ratios and Cl/Cl-2 density ratios as meas ured by molecular beam mass spectrometry. Comparisons of results from the zero-dimensional model and a two-dimensional continuum plasma mode l, using the same reaction mechanisms, further validate the chemistry set and show the strengths and weaknesses of the well-stirred reactor approach. Sensitivity analysis shows the dominant reactions contributi ng to model predictions of species densities. (C) 1998 American Vacuum Society. [S0734-2101(98)09904-7].