Managing arsenic in GaAs fab wastewater

The unprecedented demand for gallium arsenide integrated circuits presents manufacturers with a significant challenge, to maintain compliance with wastewater discharge limits for arsenic. Violating this limit can result in fines, interruption of operations, and even criminal liability. Recent action in the US regulatory arena suggests that this limit is likely to decrease dramatically in the near future. Consequently, management of this aspect of gallium arsenide manufacturing could have a significant impact on sustaining fab operations. The characteristics of typical arsenic-contributing wastewater streams are described as well as the processes and associated chemistry employed in conventional arsenic treatment. A brief overview of advanced and emerging technologies is presented as well as some of the results of recent evaluations in the Motorola “CS1” wastewater treatment operations