Removing Arsenic from GaAs Process Wastewater
Peterson, Joel (Motorola SPS, Tempe, AZ)
The recent increase in demand for gallium arsenide (GaAs) integrated circuits presents manufacturers with many significant challenges, including compliance with arsenic wastewater discharge limits. 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 substantially in the near future. Consequently, managing this aspect of GaAs device processing could have a significant impact on sustaining fab operations. The characteristics of arsenic-bearing wastewater streams are described as well as the processes and associated chemistries employed in conventional arsenic removal. The behavior of GaAs particles are described and their interaction with conventional removal processes is discussed. A brief overview of available and emerging technologies for the removal of arsenic is presented as well as the results of recent treatment advancements in the Motorola "CS1" wastewater treatment operations.
[abstract as .pdf]