Diagramm Poly-Si Chemical Vapor Deposition

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Poly Silicon Chemical Vapor Deposition

The GEC’s CVD-Reactors are designed for the deposition of the Poly Silicon. The material used for the deposition process will be high- purity Trichlorosilane mixed with high purity Hydrogen.
The Trichlorosilane will be mixed with the Hydrogen and supplied to the Reactor through multiple jets, which are integrated into the base-plate of the Reactor. Integrated into the base-plate are also 54 power supply Electrodes. The electrodes head consists of silver plated brass.
The connection parts to the 54 Filaments are of graphite material, designed by GEC and supplied by client. The deposition of the Poly Silicon happens concentrically, up to a diameter of approx. max.170 mm. 

The process requires a certain surplus on SiHCL3 and H2.This surplus will be vented over the base-plate and has to be leaded to a recovery/recycling system, a purification distillation system, for direct re-use of SiHCl3 and H2 in the Mixed-gas supply system, and conversion of SiCl4 by hydrogenation and re-delivery of HCl-gas to the SiHCl3 generation plant. The deposition process takes approx 6 days for electronic-grade, respectively 4 days for solar-grade Si quality. The removal, cleaning and re-loading requires approx. 1 day (1 day considering experienced operators).