High Purity Metal Production Using Dry Refining Processes

Two different types of dry refining and bulk formation processes and thin film formation by the Gas Deposition Method have been studied using GD-MS, IGF-IR, N2 Carrier Gas Extraction Method and CPAA, from view point of purification. Aluminum purification using liquid/solid phase under high vacuum and bulk formation of high purity tungsten by CVD method have been successfully achieved. The purity level of the purified aluminum is nearly 6N in metallics with extremely low hydrogen and oxygen contents (min. 40 ppb). The purity level of CVD-W succeeds more than 7N in metallics with extremely low oxygen contents (3.2 ppm) having high relative density 99.80%. Copper thin films formed by the Gas Deposition Method have higher purity, as purification mechanism works till and during film formation, and the resistivity of film, 20 nΩ·m, is very close to that of the bulk.