SRS could be considered one of the “greenest” companies on the planet, by taking unusable silicon that has historically been land filled, and turning into a high quality, low cost feedstock that ultimately finds its way into solar PV applications which collect free power from the sun. In fact, in 2011, SRS was named “Green Company of the Year” by the Small Business Administration and the Pacific Coast Business Times (read the article).
How Do We Do It:
SRS has an industry leading multi-step process that culminates with an innovative acid etching process enabling SRS to achieve tremendous surface purity. The SRS process includes:
Testing Materials (specifically remelt) for type, P or N and resistivity. This enables SRS to bin material based on resistivity enabling greater downstream control of the customer’s doping schedule.
Sizing Materials to our internal product specifications as well as our customer’s specific size and distribution requirements. SRS can size polysilicon and remelt materials from 400+mm down to 5mm with a combination of its breaking and state of the art crushing process.
Inspecting Material is critical to remove contamination from the process in the case of off-spec or contaminated materials. SRS has inspected over 25,000 metric tons of material since its inception and has remove contaminants such as quartz, marker, epoxy, glue, carbon, and any other foreign materials that have been present.
Our Highly Automated Acid Etching Process is the industry leader in terms of quality and capability. This innovative process can etch material down to 5 mm and up to 150 mm at semiconductor surface purity levels (< 1 ppbw total 18-metals). This proprietary designed and custom fabricated system was designed specifically to meet our requirements and to maximize both material yield and obtain industry leading surface purity levels. The subsequent results allow our customers to achieve substantial improvements in Cz puller productivity, significant increases in minority carrier lifetime cut-off, reduced dip ratios and providing the industry leading seed material for high-efficiency casting while simultaneously reducing dislocation density. All of this leads to significant cost savings.
Analytic Data are provided to each customer on a lot basis detailing specific elemental purity levels (10 or 18 total metal totals). This provides our customers with further assurance as to the quality of the material and with a distinct advantage in their growing operations by minimizing process development time.