GTAT introduces innovation to reduce polysilicon costs by $2/kg

Equipment supplier GT Advanced Technologies (GTAT) has developed polysilicon tube filaments as an alternative to conventional slim rods for more efficient chemical vapor deposition (CVD) of silicon from trichlorosilane in rod reactors (Siemens process).

In its promotional video, GTAT graphically describes several advantages of the patented innovation:

• Tube filaments offer a larger surface area available for silicon growth than slim rods do.
• Tubes are intrinsically more stable than rods. Consequently, a pair of tube filaments that are connected with a bridge (a so-called hairpin) can be made taller to produce longer polysilicon rods. Moreover, the hollow design allows for larger rod diameters without risking melt out of the core.

GTAT promises that taller rods with larger diameters can thus achieve a production capacity increase of 75% while reducing energy consumption by 20%, which would result in cost savings of over $2/kg.

The company says it is establishing a manufacturing facility for tube filaments in Asia in 2017 and will make commercial-scale volumes available starting in 2018.

If GTAT’s innovation can come anywhere close to the promised values in real-world polysilicon plants, it will cement the dominance of the Siemens process in the polysilicon industry.