PIC-MCC/Fluid Hybrid Model for Low Pressure Capacitively Coupled O{sub 2} Plasma

Journal Article · Fri May 20 00:00:00 EDT 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3562780· OSTI ID:21511566

Bera, Kallol; Rauf, Shahid; Collins, Ken ^[1]

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1. Applied Materials, Inc., 974 E. Arques Ave., M/S 81517, Sunnyvale, CA 94085 (United States)

Low pressure capacitively coupled plasmas are extensively used for advanced microelectronic device fabrication. Due to long electron mean free path and large bias voltages in this regime, kinetic effects play an important role in the dynamics of low pressure discharges. To take account of the kinetic effects, a one-dimensional hybrid plasma model has been developed that couples the Particle-In-Cell (PIC) technique for charged species and a fluid method for neutral species. The PIC model uses the Monte Carlo Collision (MCC) method to account for collision processes. The fluid model for neutral species takes into account species transport in the plasma, chemical reactions, and surface processes. An electronegative O{sub 2} plasma is simulated for a range of pressures (10-300 mTorr) and rf voltages (200-600 V) at 60 MHz. Our model for the O{sub 2} plasma considers electrons, O{sub 2}{sup +}, O{sup -}, O, and O*. The reaction mechanism includes electron impact dissociation, ionization, dissociative attachment and ion-ion recombination. Computational results are compared to our previous simulations for an electropositive Ar discharge. The electrons primarily absorb power from the external power supply at the sheath edge during sheath expansion. Energetic beam electrons are generated at the sheath edge during electron heating, which are responsible for plasma production and sustenance through collisions. The negative ions are found to be confined in the bulk plasma due to the potential well. The ratio of negative ions to electrons increases with increase in pressure and decrease in rf voltage. The spatial profiles of charged and neutral species in the plasma are found to primarily depend on species sources due to collisional processes.

• OSTI ID: 21511566
• Journal Information: AIP Conference Proceedings, Vol. 1333, Issue 1; Conference: 27. international symposium on rarefied gas dynamics, Pacific Grove, CA (United States), 10-15 Jul 2010; Other Information: DOI: 10.1063/1.3562780; (c) 2011 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANIONS
BEAMS
COLLISIONS
DISSOCIATION
ELECTRIC DISCHARGES
ELECTRONS
FLUIDS
HYBRID SYSTEMS
IONIZATION
MEAN FREE PATH
MOLECULES
MONTE CARLO METHOD
ONE-DIMENSIONAL CALCULATIONS
OXYGEN
PLASMA
PLASMA PRODUCTION
REACTION KINETICS
RECOMBINATION
SIMULATION
SURFACES
CALCULATION METHODS
CHARGED PARTICLES
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
IONS
KINETICS
LEPTONS
NONMETALS