As one of the most used material in the semiconductor and photovoltaic markets, silicon is traditionally produced via the tedious Siemens method which require several repetitions of the process stages. While recent advances to produce solar-grade silicon are more cost-effective (monosilane pyrolysis in a fluidized bed reactor), the processes also dictate the use of high quality raw materials that need to undergo a minimum of three purification stages (direct purification of metallurgical-grade silicon), implying the need for the development of energy-efficient and simplified processes to produce high purity silicon.
The technology on offer provides two methods that resolves the limitations of existing processes to obtain high purity silicon and are suitable for countries with no deposits of natural quartzite and coal, but with large resources of quartz sand, cheap aluminum and cheap energy. The two methods of producing high purity silicon and silicon-containing compounds include:
i. Alumothermic reduction of silica sand in an induction melting furnace to produce polysilicon of 6N (99.9999%) and higher
ii. Ternary alloy route processes to produce gaseous monosilane obtain polysilicon of highest purity above 10N (99.99999999%)
Licensing of the technology includes transfer of know-how, design services and organization of relevant production.
Both methods to produce high purity silicon have the following attributes:
Potential applications include (but are not limited to):