Effect of Buoyancy, Susceptor Motion, and Conjugate Transport in Chemical Vapor Deposition Systems

1999 ◽  
Vol 121 (3) ◽  
pp. 757-761 ◽  
Author(s):  
W. K. S. Chiu ◽  
Y. Jaluria
Keyword(s):  
Heat Transfer ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Film Deposition ◽  
Reactor Wall ◽  
Transfer Rates ◽  
Thermal Buoyancy ◽  
Flow And Heat Transfer ◽  
Feasible Alternative

The fluid flow and heat transfer in the chemical vapor deposition (CVD) manufacturing process are studied numerically. Several crucial aspects such as thermal buoyancy, continuous processing, and conjugate transport are considered. For each aspect, the predicted heat transfer rate and the susceptor temperature are computed and qualitatively linked with the rate and uniformity of film deposition. It is shown that buoyancy effects in helium carrier gas commonly used in diffusion-limited CVD has a negligible effect on deposition rates. Susceptor motion is shown as a feasible alternative to improving the productivity. Conjugate heat transfer effects that arise demonstrate that reactor wall thickness and material may be judiciously chosen to improve temperature uniformity and enhance heat transfer rates, thereby improving deposition rate, film uniformity, and quality.

A Numerical Model of the Flow and Heat Transfer in a Rotating Disk Chemical Vapor Deposition Reactor

1987 ◽  
Vol 109 (4) ◽  
pp. 928-935 ◽  
Author(s):  
G. Evans ◽  
R. Greif
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Finite Size ◽  
Chemical Vapor ◽  
Rotating Disk ◽  
Temperature Fields ◽  
Navier Stokes ◽  
Flow And Heat Transfer

Steady, laminar, axisymmetric, and circumferentially uniform flow and heat transfer, including the effects of variable properties and buoyancy, have been modeled within a rotating disk chemical vapor deposition (CVD) reactor. The reactor is oriented vertically, with the hot, isothermal, spinning disk facing upward. The Navier–Stokes and energy equations have been solved for the carrier gas helium. The solutions have been obtained over a range of parameters, which is of importance in CVD applications. The primary parameters are the ratio of the disk temperature to the free stream temperature Tw/T∞, the disk Reynolds number Re = rd2ω/ν∞, a mixed convection parameter Gr/Re3/2 = g(ρ∞ − ρw)/(ρwωων∞), the dimensionless inlet velocity u∞/ων∞, and two geometric parameters ro/rd and L/rd. Results are obtained for the velocity and the temperature fields and for the heat flux at the surface of the rotating disk. Comparisons are made with the one-dimensional, variable-property (excluding buoyant effects), infinite rotating disk solutions of Pollard and Newman. Results are presented in terms of a local Nusselt number. The potential uniformity of CVD in this geometry can be inferred from the variation of the Nusselt number over the surface of the rotating disk. The effects of buoyancy and the finite size of the rotating disk within the cylindrical reactor are clearly evident in the present work.

Gas flow and heat transfer in a pancake chemical vapor deposition reactor

1995 ◽  
Vol 151 (3-4) ◽  
pp. 375-383 ◽  
Author(s):  
Hitoshi Habuka ◽  
Masanori Mayusumi ◽  
Naoto Tate ◽  
Masatake Katayama
Keyword(s):  
Heat Transfer ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Reactor ◽  
Flow And Heat Transfer

Nucleation and selected area deposition of diamond by biased hot filament chemical vapor deposition

1995 ◽  
Vol 10 (2) ◽  
pp. 425-430 ◽  
Author(s):  
W. Zhu ◽  
F.R. Sivazlian ◽  
B.R. Stoner ◽  
J.T. Glass
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
Wire Mesh ◽  
Reactor Wall ◽  
Nucleation Density ◽  
Si Substrate ◽  
Diamond Nucleation ◽  
Hot Filament

This paper describes a process for uniformly enhancing the nucleation density of diamond films on silicon (Si) substrates via dc-biased hot filament chemical vapor deposition (HFCVD). The Si substrate was negatively biased and the tungsten (W) filaments were positively biased relative to the grounded stainless steel reactor wall. It was found that by directly applying such a negative bias to the Si substrate in a typical HFCVD process, the enhanced diamond nucleation occurred only along the edges of the Si wafer. This resulted in an extremely nonuniform nucleation pattern. Several modifications were introduced to the design of the substrate holder, including a metal wire-mesh inserted between the filaments and the substrate, in the aim of making the impinging ion flux more uniformly distributed across the substrate surface. With such improved growth system designs, uniform enhancement of diamond nucleation across the substrate surface was realized. In addition, the use of certain metallic wire mesh sizes during biasing also enabled patterned or selective diamond deposition.

Metal-organic chemical vapor deposition of ZrO2 films using Zr(thd)4 as precursors

1994 ◽  
Vol 9 (7) ◽  
pp. 1721-1727 ◽  
Author(s):  
Jie Si ◽  
Seshu B. Desu ◽  
Ching-Yi Tsai
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Film Deposition ◽  
Organic Chemical ◽  
Deposition Rates ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Deposited Films

Synthesis of zirconium tetramethylheptanedione [Zr(thd)4] was optimized. Purity of Zr(thd)4 was confirmed by melting point determination, carbon, and hydrogen elemental analysis and proton nuclear magnetic resonance spectrometer (NMR). By using Zr(thd)4, excellent quality ZrO2 thin films were successfully deposited on single-crystal silicon wafers by metal-organic chemical vapor deposition (MOCVD) at reduced pressures. For substrate temperatures below 530 °C, the film deposition rates were very small (⋚1 nm/min). The film deposition rates were significantly affected by (i) source temperature, (ii) substrate temperature, and (iii) total pressure. As-deposited films are carbon free. Furthermore, only the tetragonal ZrO2 phase was identified in as-deposited films. The tetragonal phase transformed progressively into the monoclinic phase as the films were subjected to a high-temperature post-deposition annealing. The optical properties of the ZrO2 thin films as a function of wavelength, in the range of 200 nm to 2000 nm, were also reported. In addition, a simplified theoretical model which considers only a surface reaction was used to analyze the deposition of ZrO2 films. The model predicated the deposition rates well for various conditions in the hot wall reactor.

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