J. Phys. IV France 09 (1999) Pr8-251-Pr8-258
Modeling of mass-transportation of tris-(acetylacetonato)chromium(III) at atmospheric pressureN.E. Fedotova1, A.N. Mikheev1, N.V. Gelfond1, I.K. Igumenov1, N.B. Morozova1 and R.H. Tuffias2
1 Institute of Inorganic Chemistry, Ave. Acad. Lavrent'ev 3, 630090 Novosibirsk, Russia
2 Ultramet Inc., 12173 Montague Street, Pacoima, CA 91331, U.S.A.
The main requirement to "hot" sources for MO CVD processes is stability of precursor vapor concentration in the area of substrate surface. Establishing the mathematical models of sublimation process of precursor will allow greatly to accelerate a transition from results of the concrete experiment to the "hot" source development with necessary parameters. Possibility of elaborating similar mathematical model taking into account totality of experimental parameters was approved on the example of description of sublimation process of tris-(acetylacetonato)chromium(III) (Cr(acac)3). Modeling of sublimation process of Cr(acac)3 for different conditions of experiment was carried out with using the notions of heat-mass-exchange theory. Criteria dependency satisfactory describing influence of experimental parameters on the rate of sublimation of molecular crystals of volatile Cr(acac)3 was obtained. An empirical correlation, J=Const×T2.18×V0.43×esp(-ΔH/RT)×W1.62×L0.386, is proposed to describe the rate of mass transfer. The W and L-are width and length of sample, accordingly. This model satisfactory describes the whole collection of experimental data and ensures forecasting of sublimation rate under other conditions of the performance of the process.
© EDP Sciences 1999