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The entire know-how and services from one single source.
With more than 220 employees, engineers with various specializations and over 140 years of company tradition, the EPC Group is known for high-quality processes and systems. Our portfolio of services contains not only the planning and provision of equipment for TCS synthesis and also vents gas recovery systems, but also rectification units, in which the know-how of experienced experts is required. We also provide you with the subsidiary systems, infrastructure systems and construction planning services for complete factories. Customers from all over the world appreciate us as a reliable partner with individual approaches to solutions.
Slurry supply systems from EPC are safe, efficient and environmentally friendly.
Sawing processes for manufacturing silicon bricks and wafers are indispensable in the semiconductor industry. Slurry is the cutting fluid used together with diamond wire saws to cut silicon blocks into paper-thin wafers. Slurry is also produced in the production of the bricks. This fluid consists of silicon carbide dissolved in oil and glycol. EPC constructs the slurry recycling plants that separate the constituents of the fluid, and prepare them for recycling back into the manufacturing process.
Slurry supply systems from EPC are safe, efficient and environmentally friendly. We offer special, highly accurate mixing and supply systems. We also construct recycling plants that filter the water/slurry mixture used in the production processes to recover the valuable constituents. This recovery process not only minimizes storage and transport costs but also reduces the costs of preparing ultrapure water and disposing of waste water.
The method of producing ultrapure silicon from metallurgic silicon is based on the thermal decomposition of highly pure, rectified chlorosilanes or silanes to form silicon with the separation and recycling of gaseous byproducts. The conventional commercial technology passes through the stage of producing trichlorosilane in a fluidized-bed reactor from metallurgic grade silicon and hydrogen chloride. The trichlorosilane is then subjected to multi-stage rectification until the purity required for the desired application is reached (solar grade or electronic grade). The thermal decomposition of trichlorosilane in a chemical vapor deposition (CVD) reactor to form silicon at 900 °C creates a mixture of gaseous by-products, which have to be prepared for recycling (vent gas recovery) back into the process. We have optimized the process for producing ultrapure silicon from monosilane. It now offers a significantly higher efficiency as temperatures are only around 600 °C, and the collection efficiency has been increased to almost 100% in comparison to the mere 25% achieved by conventional processes. Monosilane is obtained by the disproportionation of trichlorosilane and recirculation of the disproportionation products. Trichlorosilane is thus required in both methods.
The gas mixture produced by the thermal decomposition of trichlorosilane in a chemical vapor deposition (CVD) reactor has to be separated into its constituent parts before the individual products can be recirculated. The monosilane method does not need these cycles, however Vent Gas Recovery is still part of our range or products.
The monosilane synthesis gas is stored temporarily in vacuum-insulated containers prior to further processing or filling. The containers are equipped with a pressure build-up vaporizer and an internal cooling coil to facilitate cooling. The containers are a special product of our subsidiary company, CRYOTEC, which specializes in special cryogenic applications.
Silicon tetrachloride is the main by-product of both the production of trichlorosilane from metallurgic silicon with HCl in a fluidized-bed reactor and the disproportionation of trichlorosilane. The thermal decomposition of trichlorosilane in a CVD reactor also creates large quantities of silicon tetrachloride. The silicon tetrachloride is converted with hydrogen into trichlorosilane in a conversion reactor. This process can be run homogeneously with hydrogen at approximately 1,000 °C in graphite reactors. We use the more elegant heterogeneous method of controlling the process by feeding silicon into a fluidized-bed reactor.