The fabrication of microelectronic devices is largely based on the use of chemical reactions - photochemistry, etching and deposition - to construct integrated circuits. The need for exquisite control of these reactions and their inherent complexity makes computer simulation of process steps in device fabrication a useful tool. Comparison of modeling results to experimental measurement can provide insight into underlying reaction mechanisms, and "what-if" simulations can predict the consequences of proposed process, reagent and formulation modifications prior to experimental implementation.

We have constructed a set of simulation tools based on the stochastic algorithm of Bunker¹ and Gillespie² that can be applied to evaluate kinetics of both homogeneous and spatially heterogeneous systems. These tools have been used to study temperature programmed desorption³, film growth⁴ and heat flow⁵. Most recently we have applied kinetic analyses to examine chemical and physical details of steps in the photolithographic process, the basic method for defining circuitry patterns.

Examples of such application include

• an experimental and kinetic modeling study of image blur⁶ in chemically amplified resists;
• Experimental studies of the kinetics of reactive dissolution of thin polymer films⁷; and
• A numerical analysis of the ultraviolet photochemistry of water⁸ in deep-ultraviolet immersion lithography.

 References

1. D. L Bunker, B. Garrett, T. Kleindienst and G. S. Long, III, Combust. Flame, 23, 373 (1974).
2. D. Gillespie, J. Comput. Phys., 22, 403 (1976).
3. F. Houle and W.Hinsberg, Surface Science, 338, 329-346 (1995).
4. F. Houle and W. Hinsberg, J. Phys. Chem., 99, 14477-14485 (1995).
5. F. A.Houle and W. Hinsberg, Applied Physics A, 66, 143-151 (1998).
6. F. A. Houle, W. D. Hinsberg, M. Morrison, M. I. Sanchez, G. Wallraff, C. Larson, J. Hoffnagle, J. Vac. Sci. Techn. B, 18, 1874-1885 (2000).
7. W. Hinsberg, F.A. Houle, S-W Lee H. Ito and K. Kanazawa, Macromolecules, 38, 1882-1898 (2005).
8. W. Hinsberg and F. Houle, J. Vac. Sci. Techn. B, 23, 2427-2435 (2005).