How to Make Good Use of Low Utilization Rates
By Joseph Farah
Although a key goal in semiconductor manufacturing is to run tools and fabs at high rates of utilization, soft end-markets or other factors can make that harder to achieve. But manufacturers can turn periods of lower utilization to their benefit by using the available time to take proactive steps to increase the performance and productivity of their equipment and fab operations. In this edition of Tool Talk, I’ll discuss some of the specific areas that can be addressed.
Among these are tasks that can take more than a few hours to accomplish, such as annual preventive maintenance services, CIP upgrades, non-standard, optional major upgrades, and maybe even chamber reconfigurations. In addition, other tasks such as parts qualification, system baseline/benchmarking, and planning for ramps can be carried out.
Applied Global Services (AGS) works with customers to plan, schedule and implement all of these, and here are some recommendations for the areas we target.
Benchmarking the Tools (Applied FabVantage® 360™)
FabVantage 360 is AGS’ industry-leading benchmarking offering, designed to help customers run more efficient systems that deliver the highest performance, output and yield. During FabVantage 360 engagements, AGS experts with specialized, hands-on experience and tool knowledge benchmark the customer’s system against our global installed base of similar applications, hardware configurations and software functionality.
The customer receives a report that identifies and quantifies gaps to world class performance on two dozen metrics in the areas of hardware and software setup, maintenance, process control, unit process performance, and output. These gaps indicate improvement opportunities and help the customer calculate an ROI for improvement projects.
Examples of non-BKM system setup might include using older 300mm Generation 3 system computers instead of the new Generation 4 computers; or using legacy VME controllers on 200mm systems instead of the newer Applied Vita™ controllers. Other system setup findings might be particle reduction by upgrading to L-Motion actuation for slit valves and more advanced robotic systems on the Applied Materials Producer® SE tools (figure 1).
Figure 1. Upgrades to Applied tools that can be made during low-utilization periods include (from left) the Applied Vita system controller, which brings state-of-the-art sensing, control, diagnostic, communications and other capabilities to tools; an L-Motion slit valve to close an opening in a vacuum chamber with just one motion; and Applied’s vFX robotic wafer-handling system, which can simultaneously transfer multiple wafers between paired processing stations.
Many tool upgrades from AGS can be available within a few weeks of ordering, enabling customers to perform system upgrades to address obsolescence as well as to improve the functionality of certain parts. For instance, many systems running older software with aging servers can be upgraded to modern, state-of-the-art servers that offer new and more powerful processors, bigger hard drives and improved memory. And more versatile wafer-handling robots can provide more accurate wafer placement in chambers, are much more efficient and reliable, and offer lower overall costs. Many upgrades have been developed to improve chamber performance by tightening on-wafer uniformity, reducing particles, and extending preventive maintenance intervals. These upgrades can impact the customer’s yield and cost. Additionally, Applied Materials has developed mainframe and chamber upgrades that can increase throughput.
Many customers choose to idle tools that are not needed for production, and often this is not problematic if power, heaters and purging are still available. However, idling and shutting a system down for a few days, weeks or a month can cause pumps to seize and fail to re-start. Instead of idling a tool by simply stopping the pump, manufacturers can implement a higher level of system intelligence, such as that of Applied’s new Aeris™-S plasma abatement system. It delivers more sophisticated power control capabilities, while inline abatement can be used to keep the pump and foreline clean, thereby reducing risk to the pump (figure 2).
Figure 2. Applied’s Aeris-S plasma abatement system reduces foreline clogging and protects dry pumps.
Apart from idling, more sophisticated pump control can reduce the power needed during production, helping pumps to run more efficiently and save energy. It also allows for purge gas volumes to be reduced with no impact on defectivity. (See New Aeris Systems for Handling Chamber-Exhaust)
Parts Stocking and New Parts Qualifications
Parts stocking during a period of low fab utilization is perhaps one of the most logical and common areas of preparation for a forthcoming ramp. AGS recommends planning and stocking preventive maintenance parts, along with constrained parts such as heaters and faceplates, to reduce the risk of their being unavailable at ramp time. In addition, periods of low utilization are ideal times in which to qualify new parts that meet the same spec but are available at lower cost, as well as enhanced parts that provide greater benefits such as better uniformity or higher output.
Time is Money
In a fab, time is perhaps the most valuable resource, and taking advantage of the time available during low-utilization periods enables manufacturers to undertake tasks that are normally pushed out on the schedule. Benchmarks, upgrades, smart idle and parts stocking are some of the many areas that can be addressed to prepare for forthcoming product ramps, to avoid obsolescence, to improve system performance and to qualify new parts.
As always, we are fully committed to providing our customers with top notch support. We recommend customers use our Applied OnDemand™ service for overall system checks and health assessments. To learn more, call the Applied Materials Global Customer Contact Center at 1-800-468-8888 (1-800-HOT-TTTT) and a local Field Service representative will contact you promptly. Or reach us by email at www.GCC_AMNA@amat.com, or online at www.appliedmaterials.com/customer-portal.
Joseph Farah is Applied’s Director of Product Line Management. You can reach him at email@example.com.