scholarly journals Computational Fluid Dynamics Analysis of Particle Deposition Induced by a Showerhead Electrode in a Capacitively Coupled Plasma Reactor

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1004
Author(s):  
Ho Jun Kim ◽  
Jung Hwan Yoon

Defect formation in the deposition of thin films for semiconductors is not yet sufficiently understood. In a showerhead-type capacitively coupled plasma (CCP) deposition reactor, the showerhead acts as both the gas distributor and the electrode. We used computational fluid dynamics to investigate ways to enhance cleanliness by analyzing the particle deposition induced by the showerhead electrode in a CCP reactor. We analyzed particle transport phenomena using a three-dimensional complex geometry, whereas SiH4/He discharges were simulated in a two-dimensional simplified geometry. The process volume was located between the RF-powered showerhead and the grounded heater. We demonstrated that the efficient transportation of particles with a radius exceeding 1 μm onto the heater is facilitated by acceleration inside the showerhead holes. Because the available space in which to flow inside the showerhead is constricted, high gas velocities within the showerhead holes can accelerate particles and lead to inertia-enhanced particle deposition. The effect of the electrode spacing on the deposition of particles generated in plasma discharges was also investigated. Smaller electrode spacing promoted the deposition of particles fed from the showerhead on the heater, whereas larger electrode spacing facilitated the deposition of particles generated in plasma discharges on the heater.

2010 ◽  
Vol 17 (01) ◽  
pp. 45-49
Author(s):  
KYUBONG JUNG ◽  
WOOJIN SONG ◽  
DOO-MAN CHUN ◽  
JUN-CHEOL YEO ◽  
MIN-SAENG KIM ◽  
...  

A micronozzle was applied in nanoparticle deposition system (NPDS) for supersonic deposition. To determine whether suitable behavior of supersonic fluid can be produced or not, computational fluid dynamics (CFD) flow analysis was used. Ni particles were successfully deposited using the fabricated micronozzle in NPDS at room temperature. It was found that shorter micronozzle with larger side profile deposits wide and thick film compared to the deposition using long micronozzle with smaller side profile. These experimental results agree with the simulation results.


Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 999
Author(s):  
Ho Jun Kim

Increasing the productivity of a showerhead-type capacitively coupled plasma (CCP) reactor requires an in-depth understanding of various physical phenomena related to the showerhead, which is not only responsible for gas distribution, but also acts as the electrode. Thus, we investigated how to enhance the cleanliness and deposition rate by studying the multiple roles of the showerhead electrode in a CCP reactor. We analyzed the gas transport in a three-dimensional complex geometry, and the SiH4/He discharges were simulated in a two-dimensional simplified geometry. The process volume was installed between the showerhead electrode (radio frequency powered) and the heater electrode (grounded). Our aim of research was to determine the extent to which the heated showerhead contributed to increasing the deposition rate and to reducing the size of the large particles generated during processing. The temperature of the showerhead was increased to experimentally measure the number of particles transported onto the heater to demonstrate the effects thereof on the decrease in contamination. The number of particles larger than 45 nm decreased by approximately 93% when the showerhead temperature increased from 373 to 553 K.


Author(s):  
P.E. Nylén ◽  
R. Bandyopadhyay

Abstract The industrial flame spraying process has been analyzed by three-dimensional Computational Fluid Dynamics (CFD) simulation. The actual process is employed at the Volvo Aero Corporation for coating of fan and compressor housings. It involves the Metco 6P gun where the fuel, a mixture of acetylene and oxygen, flows through a ring of 16 orifices, while the coating material, a powder of nickel-covered bentonite, is sprayed through the flame with a stream of argon as a carrier gas by a central orifice. The gas flow was simulated as a multi-component chemically reacting incompressible flow. The standard, two equations, k-e turbulence model was employed for the turbulent flow field. The reaction rates appeared as source terms in the species transport equations. They were computed from the contributions of the Arrhenius rate expressions and the Magnussen and Hjertager eddy dissipation model. The particles were modeled using a Lagrangian particle spray model. In spite of the complexity of the system, the complex geometry and the numerous chemical reactions, the simulations produced fairly good agreement with experimental measurements. The powder size distribution was found to play a critical role in the amount of unmelted fraction of particles. The modeling approach seems to give a realistic description of the physical phenomena involved in flame spraying, albeit some model refinement is needed.


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