Investigation of the DSMC Approach for Ion/neutral Species in Modeling Low Pressure Plasma Reactor

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

DOI:https://doi.org/10.1063/1.3562781· OSTI ID:21511567

Hao, Deng; Li, Z; Levin, D ^[1]; Gochberg, L ^[2]

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1. Department of Aerospace Engineering, Pennsylvania State University, University Park, PA 16802-1441 (United States)
2. Gochberg Group, Latham, NY 12110-4726 (United States)

Low pressure plasma reactors are important tools for ionized metal physical vapor deposition (IMPVD), a semiconductor plasma processing technology that is increasingly being applied to deposit Cu seed layers on semiconductor surfaces of trenches and vias with the high aspect ratio (e.g., >5:1). A large fraction of ionized atoms produced by the IMPVD process leads to an anisotropic deposition flux towards the substrate, a feature which is critical for attaining a void-free and uniform fill. Modeling such devices is challenging due to their high plasma density, reactive environment, but low gas pressure. A modular code developed by the Computational Optical and Discharge Physics Group, the Hybrid Plasma Equipment Model (HPEM), has been successfully applied to the numerical investigations of IMPVD by modeling a hollow cathode magnetron (HCM) device. However, as the development of semiconductor devices progresses towards the lower pressure regime (e.g., <5 mTorr), the breakdown of the continuum assumption limits the application of the fluid model in HPEM and suggests the incorporation of the kinetic method, such as the direct simulation Monte Carlo (DSMC), in the plasma simulation.The DSMC method, which solves the Boltzmann equation of transport, has been successfully applied in modeling micro-fluidic flows in MEMS devices with low Reynolds numbers, a feature shared with the HCM. Modeling of the basic physical and chemical processes for ion/neutral species in plasma have been developed and implemented in DSMC, which include ion particle motion due to the Lorentz force, electron impact reactions, charge exchange reactions, and charge recombination at the surface. The heating of neutrals due to collisions with ions and the heating of ions due to the electrostatic field will be shown to be captured by the DSMC simulations. In this work, DSMC calculations were coupled with the modules from HPEM so that the plasma can be self-consistently solved. Differences in the Ar results, the dominant species in the reactor, produced by the DSMC-HPEM coupled simulation will be shown in comparison with the original HPEM results. The effects of the DSMC calculations for ion/neutral species on HPEM plasma simulation will be further analyzed.

• OSTI ID: 21511567
• 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: 10.1063/1.3562781; (c) 2011 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANISOTROPY
ASPECT RATIO
BOLTZMANN EQUATION
CHARGE-EXCHANGE REACTIONS
FLUIDS
IONIZATION
IONS
LAYERS
LORENTZ FORCE
MAGNETRONS
MICROSTRUCTURE
MONTE CARLO METHOD
PHYSICAL VAPOR DEPOSITION
PLASMA DENSITY
PLASMA SIMULATION
RECOMBINATION
REYNOLDS NUMBER
SEMICONDUCTOR MATERIALS
SUBSTRATES
SURFACES
CALCULATION METHODS
CHARGED PARTICLES
DEPOSITION
DIFFERENTIAL EQUATIONS
DIMENSIONLESS NUMBERS
ELECTRON TUBES
ELECTRONIC EQUIPMENT
EQUATIONS
EQUIPMENT
INTEGRO-DIFFERENTIAL EQUATIONS
KINETIC EQUATIONS
MATERIALS
MICROWAVE EQUIPMENT
MICROWAVE TUBES
NUCLEAR REACTIONS
PARTIAL DIFFERENTIAL EQUATIONS
SIMULATION
SURFACE COATING