Production of Semiconductor Grade Crystals from Recovered GaAs and InP Manufac

On-site recovery of constituent materials from compound semiconductor waste streams presents an opportunity for reduction of hazardous material waste and cost of manufacturing. UDRI has developed a low-cost process for recovering gallium and arsenic from the production of gallium arsenide where the primary contaminant is the other element of the binary compound. This method can be applied to other compound semiconductors also. AXT proposes to grow gallium arsenide crystals from waste materials recovered by the UDRI process from AXT's normal gallium arsenide substrate manufacturing production line. The crystals will be wafered and analyzed by typical compound semiconductor analysis techniques such as Hall effect, GDMS, X-ray, etc. to determine what level of binary residual can be successfully used to grow high quality crystals. Additionally, preliminary studies will be made to determine the concentration of contaminants in the recovered gallium and arsenic and their impact on the purity of the grown crystals. Since the typical starting materials are 6-7N purity, the on-site recovered materials may retain similar purity after the UDRI process. Successful demonstration of crystal growth will pave the way for implementation of the recovery process in a commercial volume-production environment. Successful implementation of the on-site recovery technology can lead to reduction in waste and cost of compound semiconductor crystals. Localized waste recovery avoids the cost of landfill and future potential hazards.