Low pressure, cold (gas temperature 300 K to 500 K),weakly ionized plasma discharges are used extensively in semiconductor device fabrication especially for deposition and etching of thin films. In plasma CVD, the electrons decompose the flowing feed stock gas into radicals and ions. These radicals adsorb on the wafer surface, where they react to deposit a thin film. A wide range of materials, SiO2, Si3N4, amorphous Si and many more can be deposited using plasma discharges.

Using FLUENT in conjunction with PLASMATOR, from Kinema Research and Software, we can successfully simulate both inductive and capacitively coupled discharges, and solve for a wide range of problems, including deposition, dielectric/metal etching, and reactor cleaning.

PLASMATOR utilizes a comprehensive chemistry set to characterize electron density, electron energy and electric potential. FLUENT uses this information to solve for ions, and neutral density distribution and to predict deposition.

The FLUENT/PLASMATOR joint product accurately and efficiently models inductively and capacitively coupled plasma discharges using transport coefficients based on Maxwellian energy distributions. Time-periodic CCP simulators are time-averaged to provide efficient input to quasi-steady flow predictions. The product also models multiple sets of coils with separate driving frequency and power.

Electron density (left) and electron energy (right) distributions in an inductively coupled GEC reference cell.

Rate of ionization of argon (left), and argon ion (right) density distributions in a GEC/ICP cell.