Self-consistent three-dimensional model of dust particle transport and formation of Coulomb crystals in plasma processing reactors

Vivek Vyas, Gregory A. Hebner, Mark J. Kushner
2002 Journal of Applied Physics  
Dust particle transport in low-temperature plasmas has received considerable attention due to the desire to minimize contamination of wafers during plasma processing of microelectronic devices and for their use to study nonideal plasmas. Dust particles in radio frequency discharges form Coulomb crystals and display collective behavior under select conditions. In this article, we discuss results from a self-consistent three-dimensional model for dust particle transport in plasma processing
more » ... rs. The consequences of varying the bias voltage of the capacitively coupled discharge, plasma density, particle diameter, and the number of particles on the propensity for Coulomb crystal formation in argon plasmas will be discussed. We found that a single one-layer lattice spontaneously breaks up into separate lattices as the substrate bias is increased due to a redistribution of plasma forces. At high substrate biases, a void occurs in the plasma crystal which tends to close upon addition of electronegative gases such as O 2 and Cl 2 to argon. The interparticle spacing in the lattice depends on the number of particles in the lattice due to gravitational compressive forces; and on the plasma density due to the change in shielding length.
doi:10.1063/1.1516865 fatcat:p2j4yvjdsncoboemu7345gzgxe