Modeling of tungsten thermal chemical vapor deposition

Citation
B. Kim et al., Modeling of tungsten thermal chemical vapor deposition, JPN J A P 1, 38(5A), 1999, pp. 2881-2887
Citations number
15
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Volume
38
Issue
5A
Year of publication
1999
Pages
2881 - 2887
Database
ISI
SICI code
0021-4922(199905)38:5A<2881:MOTTCV>2.0.ZU;2-P
Abstract
Low-pressure chemical vapor deposition (LPCVD) of tungsten (W) film on sili con (Si) substrate was pet-formed by reducting hexafluoride (WF6) with hydr ogen. This CVD system is known for its nonlinear dependence of growth rate on WF6 concentration. This study adopted a simple surface-reaction model wh ich assumes that the precursor, i.e., WF6, in the gas phase adsorbs on soli d surfaces and then the adsorbed WF6 molecule is converted into tungsten so lid film. The two kinetic parameters involved in the model are derived from the experimental results. The solidification rate constant (k(s)) is equal to the growth rate at very high WF6 concentrations. The adsorption rate co nstant (k(a)) is derived from profile analyses of films grown in microtrenc hes under very low WF6 concentrations by applying the conventional Monte Ca rlo simulation code, which is Valid for linear surface-reaction systems. In the temperature range of 623 to 823 K, k(a) and k(s) have activation energ ies of 82 kJmol(-1), 66.1 kJmol(-1), respectively. A newly proposed Monte C arlo simulation for nonlinear reaction systems, in combination with the two kinetic parameters, can quantitatively predict the shape of film in microt renches for a wide range of temperatures and WF6 concentrations.