Validation of a Rapid Thermal Processing model in steady-state
2008, Microelectronic Engineering
https://doi.org/10.1016/J.MEE.2008.07.012Abstract
Rapid Thermal Processing (RTP) is widely used in advanced semiconductor manufacturing. The present work deals with the heat transfer from infrared lamps to the silicon wafer in a commercial RTP equipment. Both numerical and experimental approaches are considered. For numerical purposes, the RTP system is modelled in two (2D) and three dimensions (3D). Calculations are performed in steady-state. The computational fluid dynamics method (CFD) is used for solving the mass and heat conservation equations. The radiative heat transfer equation is solved with the Monte Carlo method. In order to validate these models, measurements of the wafer temperature are realized for five electric power values supplied to the infrared lamps. The experimental wafer temperature profiles are in good agreement with the numerically calculated ones. Moreover, a confrontation between the experimental temperature of the infrared lamp filaments evaluated from the Ohm law and the one used in the numerical calculations shows a good agreement with the 3D model. The slight difference observed with the 2D model is explained. So the numerical simulations are fully validated. Two relations are established in order to predict the power which has to be applied to infrared lamps to obtain the required wafer temperature.
FAQs
AI
What explains the differences in experimental and numerical temperature profiles in RTP?
The study finds that discrepancies between experimental and calculated temperatures are less than 2% for both 2D and 3D cases, except for the 30% heating power case where differences reach up to 4.3%.
How does the steady-state temperature vary with lamp heating power?
Experimental results show that the wafer reaches steady-state conditions after 900 seconds for all heating power values of 10%-30% maximum.
What impact do dimensional models have on temperature simulation outcomes?
The 3D model provides more accurate temperature simulations than the 2D model, particularly because 2D does not realistically account for geometry, resulting in a 5-8% correction for filament temperatures.
How was the filament temperature determined during the experiments?
Filament temperature is evaluated using Ohm's law based calculations from recorded values of current intensity and voltage during the heating process.
When do the experimental and numerical simulations achieve highest correlation?
The highest correlation between experimental measurements and simulations occurs at the 20% heating power, where both models show very good agreement within ±0.4% accuracy.
References (21)
- V.E. Borisenko, P.J. Hesketh, Rapid thermal processing of semiconductors, Plenum Press, New York, 1997.
- R. Lindsay, A. Lauwers, M. de Potter, N. Roelandts, C. Vrancken, K. Maex, Microelectronic Engineering 55 (2001) 157-162.
- V.A. Matylitskaya, W. Bock, K. Thoma, B.O. Kolbesen, Microchimica Acta 156 (1-2) (2006) 33-37.
- J. Niess, S. Paul, S. Buschbaum, P. Schmid, W. Lerch, Materials Science and Engineering B 114-115 (2004) 141-150.
- J.L. Ebert, D. De Roover, L.L. Porter II, V.A. Lisiewicz, S. Ghosal, R.L. Kosut, A. Emami-Naeini, in: Proceedings of the American Control Conference, 5, 2004, 3910-3921.
- H. Iwai, K. Kakushima, H. Wong, International Journal of High Speed Electronics and Systems 16 (2006) 43-81.
- T.F. Edgar, S.W. Butler, W.J. Campbell, C. Pfeiffer, C. Bode, S.B. Hwang, K.S. Balakrishnan, J. Hahn, Automatica 36 (2000) 1567-1603.
- J.R. Howell, K.S. Ball, in: 12th IEEE International Conference on Advanced Thermal Processing of Semiconductors, RTP 2004, 2004, 175-180.
- P.O. Logerais, M. Girtan, A. Bouteville, Electrochemical Society Proceedings 9 (2005) 49-56.
- AS-One 150 is an AnnealSys product, Montpellier, France, <www.annealsys.com>.
- CFD'ACE software is an ESI group product, Huntsville, USA, <www.esi- group.com>.
- C.J. Smithells, Tungsten: Its Metal Properties and Applications, Chemical Publishing Company, New York, 1953, <http://www.tungsten.com/ mtstung.html>.
- Fig. 10. Relation between the lamp applied power and the wafer temperature.
- V. Versteeg, W. Malalasekera, An Introduction to Computational Fluid Dynamics. The Finite Volume Method, Longman, London, 1995.
- S.V. Patankar, Numerical Heat Transfer and Fluid Flow, Hemisphere Publishing Corporation, McGraw-Hill Book Company, New York, 1980.
- ESI group Research and Development, CFD'ACE Version 2007 User Manual, 2007.
- ESI group Research and Development, CFD'ACE Version 2007 Modules Manual, 2007.
- A. Kersch, W. Morokoff, Transport Simulation in Microelectronics, Birkhauser, Basel, 1995.
- H. Habuka, M. Shimada, K. Okuyama, Journal of the Electrochemical Society 147 (12) (2000) 4660-4664.
- S. Mazumder, A. Kersch, Numerical Heat Transfer, Part B Fundamentals 37 (2000) 185-199.
- M.F. Modest, Radiative Heat Transfer, McGraw-Hill International Editions, New York, 1993.