Increase on Siemens Reactor Throughput by Tailoring Temperature Profile of Polysilicon Rods

Siemens process productivity can be limited by non homogeneous temperature profile in polysilicon rods. To overcome this limitation high frequency current sources have been proposed. An analysis is presented which, based on electromagnetic and heat transfer theory, studies temperature and current density profiles within the rods. Two linked differential equations have been numerically solved by use of non-linear methods. The solution of these equations shows that by means of an increase in current frequency, skin effect takes place, heat generation in the inner part of the rod is decreased and therefore temperature homogeneity increases. The effect of high frequency current sources in the rod stability is also analyzed, and it can be derived that resonance problems could appear.