Growth kinetics and inhibition of growth of chemical vapor deposited thin tungsten films on silicon from tungsten hexafluoride

摘要

The growth kinetics and inhibition of growth of chemical vapor deposited thin W films on Si(100) from WF6was studied withinsitugrowth stress and reflectivity measurements andexsituweight gain measurements. A systematic series of experiments at varying WF6flow, total pressure, and temperature show that the thickening kinetics and inhibition of the growth are controlled by two processes: WF6diffusion through the gas phase and Si diffusion through the thickening columnar film. The steady state growth kinetics are controlled by WF6diffusion in the gas phase whereas inhibition of the growth occurs at the transition from WF6gas diffusion limited to Si solid state diffusion limited growth. A simple model based on WF6gas phase diffusion and Si solid state diffusion is presented which gives a quantitative description of the experimental results.