Chemical vapor deposition of semi-insulating polycrystalline silicon (SIPOS) : Experience and simulation

Abstract
SIPOS films deposited from silane and nitrous oxide find extensive applications in power components manufacturing. The deposition rate and the oxygen concentration of the SIPOS layers have been experimentally measured for various deposition temperatures and gas feeding compositions. In a second step, a theoretical model has heen developed, based on the general organization of the CVD2 software. Both hydrodynamics and mass transfer phenomena have been taken into account. A complete chemical mechanism, describing the chemistry in the gas phase inside the reactor as well as the heterogeneous reactions on the solid surfaces, has been built and several unknown kinetic constants have been determined. Simulation is in good agreement with the experience. Many information on phenomena occurring into the reactor can be obtained by the use of mathematical modeling and in particular, explanations for the radial heterogeneities on wafer and between wafers are proposed.