20 March 2014
MEI launches batch wet processing metal lift-off system
MEI Wet Processing Systems and Services (a subsidiary of MEI LLC) of Albany, OR, USA has launched the FluidJet batch wet processing system for metal lift-off in MEMS (micro-electromechanical system) and compound semiconductor manufacturing, delivering higher-yielding, more cost-effective metal lift-off processing.
MEI says that its FluidJet batch wet processing system for metal lift-off achieves breakthroughs with no metal re-deposition on either the front-side or back-side of the wafer, eliminating device damage while using 80% less chemical than existing single-wafer processing solutions. FluidJet also enables highly efficient, easily obtained gold and metal reclaim, reducing waste and downtime, adds the firm. FluidJet also saves manufacturing floor space by reducing the wet process footprint requirement by at least 60% over comparable-throughput single-wafer spray tools, it is claimed.
“By adopting the FluidJet metal lift-off system, semiconductor manufacturers will increase yield while reducing downtime and chemical costs and disposal,” reckons MEI LLC's president & CEO Dan Cappello. “As part of our metal lift-off solution, we incorporated the patent-pending FluidJet system. FluidJet processing is especially important for sensitive metal features and thin lines because the FluidJet cleans the surface gently, improving metal lift-off performance at a lower cost,” he adds. “MEI has completed numerous customer demos where side-by-side 'split lot' comparisons of lift-off performance were evaluated for several major compound semiconductor manufacturers. This data demonstrates superior performance on many lift-off and resist strip layers while reducing defects, providing significant reductions in chemical use.”
The firm says that the FluidJet metal lift-off system is unlike conventional single-wafer metal lift-off systems, using patented batch immersion processing to remove metals and eliminate re-deposition and defects. Conventional metal lift-off solutions rely on aggressive, high-pressure sprays. These high velocity sprays produce metal debris that can scratch or tear fine metal features, says MEI. Metal debris can also re-deposit, causing shorts and focus issues. The high-pressure spray at elevated temperatures is a significant factor in the consumption of massive amounts of chemical per wafer processed, adds the firm.
The FluidJet system’s self-cleaning tanks and easily accessed metal collection baskets enable lifted metals to be more easily and completely reclaimed, says MEI. Strainer baskets are emptied in minutes and sized to easily hold several thousand wafers worth of lifted metal, it adds.
FluidJet targets semiconductor and MEMS processing applications where metal lift-off is required to create create gallium arsenide (GaAs) bipolar field-effect transistor (BiFET) device structures for mobile communications devices.
MEI’s IDX proprietary control automation software mines process data from the FluidJet wet processing system, allowing engineers visibility into what is occurring in any tank or chamber. The firm also models airflow and fluid flow with special CAD software for detailed design, analysis, documentation, and configuration management. MEI leverages the CAD software’s CFD (computational fluid dynamics) capability to support its in-house engineering analysis and design of customers' process and exhaust systems.
TheFluidJet wet processing system is available for purchase immediately. Upon request, MEI will run tests for potential customers (providing verifiable data) and deliver the correct equipment needed to meet specific metal lift-off goals.