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

SIPOS films deposited from silane and nitrous oxide find extensive applicat ions in power components manufacturing. The deposition rate and the oxygen concentration of the SIPOS layers have been experimentally measured for var ious deposition temperatures and gas feeding compositions. In a second step , a theoretical model has been 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 chem istry in the gas phase inside the reactor as well as the heterogeneous reac tions on the solid surfaces, has been built and several unknown kinetic con stants have been determined. Simulation is in good agreement with the exper ience. Many information on phenomena occurring into the reactor can be obta ined by the use of mathematical modeling and in particular, explanations fo r the radial heterogeneities on wafer and between wafers are proposed.