Steven G. Barbee

Applications of computational fluid dynamics for improved performance in chemical‐vapor‐deposition reactors

Engineering models, based on computational fluid dynamics, have been developed and used to improve the performance of two metalorganic chemical‐vapor‐deposition reactors. Though the knowledge of the chemical reactions occurring during film deposition is incomplete, the models provide insight into the reactor’s performance and are useful in guiding reactor modifications. In one reactor, the effect of three gas injector designs on the film thickness uniformity is examined; in a second reactor, the shape and placement of a flow deflector, which redistributes the flow of gas over the wafer surface, is studied. In both cases, comparing the experimental results obtained both before and after the reactor modifications, significant improvements in film thickness uniformity were realized.

Temperature optimization in an azimuthally symmetric single‐wafer chemical vapor deposition reactor: The low pressure regime

A finite element model of an azimuthally symmetric single‐wafer chemical vapor deposition reactor is combined with experimental design theory to determine the influence of process and design conditions on the temperature distributions within the reactor. In such a reactor, it has been found that temperature nonuniformities as great as 15% can occur at the wafer surface and in the gas phase above the wafer. A two‐level Taguchi L16 experimental design matrix is used to evaluate the effect of five reactor design parameters and three process parameters on the temperature distributions. The reactor is operated in the ‘‘low pressure regime,’’ where heat transport between the susceptor and the wafer is by radiation only and heat transport by conduction, convection, and radiation are considered elsewhere in the reactor. Results of the analysis indicate that the susceptor radius and temperature are the dominant parameters controlling within wafer and gas phase temperature uniformity, while the thermal conductivity...