Monosilane-based polysilicon with PTR technology opens new ways to further reduce costs

The innovative, Monosilane based Schmid Technology for the production of polysilicon facilitates cost-efficient production of polysilicon in comparison to the conventional Trichlorosilane CVD. However, to obtain a silicon crystal, one has to go through the complete production process chain:

SST intends to shorten this process chain step by step by applying its patented PTR reactor concept. In an integrated process, improved energy- and material-flow management can be used for a technologically,  as well as economically, optimized production of silicon crystals.  In a first process step, PTR technology will provide granular silicon, which can be used for crystallization. This eliminates process steps of preparing filaments before, and unloading of the CVD reactor after the run.

In a second step, liquid silicon, the precursor of granular silicon, is collected directly from the PTR.  Multi-or mono crystallization process steps which nowadays have to run separately from si-feedstock production, shall be integrated into the whole process by liquid filling. This facilitates optimal use of the advantages of the plasma pyrolysis reactor, i.e.  the continuous production, as well as the granular or liquid form of the silicon and the resulting energy savings. SST expects potential savings of up to 45% compared to current crystal production costs.

PTR

Funded by the European Union and the Free State of Saxony under the title "Plasma Pyrolysis of Monosilane"