A Little Control Goes A Long Way
When NASA launched the historic Apollo space program in 1961, it pioneered a then-cutting-edge electronic guidance control system that was a clunky 70 pound technical marvel. The Apollo Guidance Computer (AGC) put 12 astronauts on the surface of the moon - then returned them safely to earth - with a mere fraction of the computing power of the ~4 ounce smartphone most of us carry in our pocket. But by 1972 the AGC could no longer adapt to the needs of advanced space exploration targeted for the next decades.
Similarly, legacy ≤200mm semiconductor production tools, many of which have been in production for ~20 years, have begun to show their limitations. With rising demand for analog, power, image sensors and MEMS products to support expanding capabilities in mobile, automotive, consumer and industrial products, most of those fabs expect to operate another 10 to 15 years. Thus, ensuring and even improving the performance of the tools is paramount.
A number of obsolescence-related issues must be addressed to ensure the tool performance of the aging 200mm fleet. Key components are a major concern. Although chamber components can usually be redesigned—often incorporating improvements based on 300mm learning to improve reliability and repeatability—system components are more challenging because they interact with, or control, multiple sub-systems of the tool. For example, 1990s-era controllers have a single-board computer architecture containing multiple obsolete electronic components and bulky CRT interfaces. Their typical control system capabilities are almost fully utilized to operate the tool, leaving limited processing power and bandwidth available to interface with fab host systems. Modern electronics would easily support much more complex processing.
That’s important, because an area of major unrealized value for most ≤200mm fabs is to improve yield and fab efficiency by implementing modern tool monitoring and advanced process control (APC) capabilities. Effective monitoring and advanced process control (APC) capability requires high speed data capture and remote connectivity for data retrieval.
The challenge of redesigning legacy controllers becomes more evident when you consider the myriad issues involved: speed, connectivity, scalability, security, dependability, user interface/experience extendibility and most of all, backward compatibility with tool’s current control software.
Ideally, a redesigned controller would provide fully transparent performance, not only with regard to the user interface, but with improved connectivity and communication capabilities to enable APC and tool monitoring. Such a control system would minimize qualification time – enabling the same recipes to be run without process change, while providing all the process monitoring and yield improvement options available at leading-edge 300mm fabs.
The challenges involved are formidable. But the mandate is clear. Just as NASA’s AGC reached its limits in enabling the next generation of space travel, it’s inevitable that legacy production tools must take a giant leap forward if subsystems like the controller are to enable continued customer success. Customers will need new controller technology to enable plug–and-play tool operation with process transparency, and with features that deliver productivity and a growth path. Equipment manufacturers must deliver the processing power that will keep providing high yield and lower costs with these workhorse tools.
For more information, please contact Cheryl_Knepfler@amat.com.