The Effects of Temperature Jump on CVD Modeling

• Published in: Chemical vapor deposition Vol. 8; no. 5; pp. 205 - 212
• Main Authors: Hu, T., Glumac, N. G.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag GmbH 01.09.2002; WILEY‐VCH Verlag GmbH; Wiley-VCH
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Gallium arsenide; Growth mechanism; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Modeling methods; Physics; Silicon carbide; Theory and models of film growth; Gallium arsenides; Inorganic compounds; Semiconductor materials; Silicon carbides; Computerized simulation; Crystal growth from vapors; Temperature jump; CVD; Surface reactions; Growth mechanism; Reaction mechanism; Models; Silicon; Kinetics; Gaseous phase reaction
• ISSN: 0948-1907; 1521-3862
• DOI: 10.1002/1521-3862(20020903)8:5<205::AID-CVDE205>3.0.CO;2-4

The effects of a temperature jump at the growth surface in stagnation flow chemical vapor deposition (CVD) reactors are investigated. General process considerations suggest that neglecting a temperature slip in modeling CVD processes can lead to an over‐ or under‐prediction of the growth if a significant temperature jump is present, and either gas‐phase reactions or a gas–surface reaction with a large kinetic energy dependence play important roles in deposition. Relationships for estimating temperature slip are reviewed, as are the mechanisms by which temperature slip can influence the deposition rate. In addition, we investigate three systems, silicon, silicon carbide, and gallium arsenide CVD, for which explicit gas‐phase and surface mechanisms exist, to estimate the influence of neglecting the temperature slip. We find that under some common process conditions, temperature jump at the substrate can be greater than 100 K. The effect on the predicted growth rate of a temperature jump of this magnitude is typically in the range 2–5 %, depending upon the kinetics of the CVD for the particular species that is deposited. The importance of accurate values of kinetic energy‐dependent gas–surface reaction rates is highlighted as a critical factor in the complete evaluation of the effects of temperature slip on growth rates in CVD. The effects of a temperature jump at the growth surface in stagnation flow CVD reactors are investigated for Si, SiC, and GaAs depositions where surface temperature jumps are predicted to occur, causing changes in the near‐surface concentrations of some key species. The predicted changes in surface flux, gas phase species concentrations, and surface reaction rates are estimated. The impact of such a temperature discontinuity on CVD modeling in general is discussed together with other factors that might counteract the outcome of such a near‐surface temperature slip.