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Stepping Back from the Canvas

New FabVantage 360™ Assessment Help Identify Gaps in Tools and Fabs

Avi Edelstein and Helen Armer

When working on a painting, artists regularly step back from the canvas to refocus and evaluate their work. Only by taking a broad view can the artist determine what’s working, what’s not, and what to do about it.[1]

Similarly, fab managers can “step back” from their overall operations to evaluate process and equipment performance. Which tools are underperforming? Are equipment constants set correctly? Could a comparison to best known methods (BKMs) help? How could uptime improve? Is my fab output as high as it could be—and am I maximizing ROI?

This article introduces a new Applied Materials benchmarking offering, FabVantage 360, which for one fab uncovered opportunities to increase output by 25% as well as reduce particles and defects.

FabVantage 360 — A Broader Perspective

To help fab executives answer the questions above and gain a better perspective on their operations, the Applied Materials FabVantage Consulting Group has developed a new assessment capability, FabVantage 360. This offering provides a differentiated benchmarking capability to identify opportunities relative to world-class performance and BKMs for evaluated toolsets.

Unlike conventional FabVantage assessments, which normally focus on a specific area of concern (such as tool output), a comprehensive FabVantage 360 evaluation delivers a much broader perspective. By taking a wider view, FabVantage 360 can identify more opportunities for tool and fab improvement and help better estimate the impact of these improvements.

Holistic Approach

A FabVantage 360 assessment compares equipment performance against similar tools across the installed base and relative to proprietary BKMs. The analysis provides a holistic view of a tool’s performance and can indicate factors that may be interdependent or hidden when the focus is limited to specific performance challenges. It also enables customers to prioritize improvement projects by quantifying the magnitude of each identified opportunity. For example, an analysis may reveal that suboptimal cleaning practices are resulting in throughput loss, higher particles, and lower uptime.

Comprehensive Scorecard

To complete an assessment, the FabVantage 360 team develops a comprehensive scorecard that benchmarks a customer’s fab performance on about two dozen metrics. The scorecard covers metrics in four categories of tool performance—configuration, maintenance, unit process, and output (see table 1). Together, these categories give a picture of a tool’s impact on fab variability, yield, and output. The metrics are scored on a scale of 0%, representing worst in class (WIC), to 100%, representing best in class (BIC).

Table 1. Metrics for tool performance used in FabVantage 360 assessments.

Typically, fab executives engage in a FabVantage 360 assessment when they need to identify opportunities to improve performance of equipment that is bottlenecked or critical for yield performance. The FabVantage 360 analysis quantifies gaps in each tool-performance metric, augmented by deep domain knowledge.

Example Scorecard

A FabVantage 360 assessment involves collecting detailed tool data from customers in exchange for providing a comprehensive scorecard that identifies tool performance gaps relative to BIC. These examples illustrates the data used to generate the scorecard, along with a summary spider chart that graphically shows performance gaps.

Figure 1 illustrates sample sections from a FabVantage 360 scorecard for a 300mm HDP UltimaX chamber used for STI gapfill in a logic fab. The results shown are representative and used for illustrative purposes only. Sections highlighted include (A) configuration, (B) maintenance, (C) unit process, and (D) output.

Nine upgrades are available for the 12 UltimaX chambers. Only the RPS bypass is installed across all chambers getting the full defects, cost, and throughput benefits. Some chambers have the GT baffle (#8) and the cool gas feed block (#9) upgrades. Other upgrades are not installed, therefore missing opportunities to reduce defects. Similarly, not all tools have the latest software installed therefore missing on latest features and causing variation across tools.

For maintenance procedures, a FabVantage 360 assessment compares the customer’s checklists to recommended checklists and frequencies. The score shows how many of the inspection, calibrations, cleaning, and replacement tasks are followed, as well as sourcing quality OEM spares for critical parts. Performance metrics are benchmarked to indicate impact on green to green time and PM success rate. In this example, the customer does not follow recommended maintenance activities and frequency and as a result takes 75h for green to green vs. 18h BIC. PM Success rate is also impacted with only 74% success, leading to more lost time and rework, as well as a quality risk.

A FabVantage 360 assessment also evaluates FDC practices by comparing the sensors the customer monitors against the list of sensors critical to the performance of a specific process. The assessment also compares general FDC practices to BKM’s and highlights areas of opportunity. This figure shows that the customer is monitoring only 51% of critical sensors and can improve sampling data rates as well as golden references. Under Particles, it also identifies a high particle count of 24 vs. benchmark of 5, representing an opportunity to reduce particles by 80%.

As shown in figure 1D, the customer’s uptime is 90.2%, within the benchmark range but scheduled downtime is close to the worst end of the benchmark, offset by good performance on unscheduled down. The performance metrics give another perspective on the PM performance with long green to green times and a low PM success rate.

To evaluate output performance, the FabVantage team assesses scheduled downtime, unscheduled downtime, and throughput against benchmark levels. FabVantage experts also analyze production runs to highlight hidden tool dedications. The analysis uncovers opportunities for process optimization and matching, leading to a more balanced utilization across tools, and therefore better cycle time through the equipment set.


Performance Gaps in Sample Evaluation

Key Takeaways

Possible issues causing poor PM performance are using non-BKM parts and not following prescribed PM procedures, such as not replacing parts at the recommended frequency and not performing prescribed calibrations. High particles are also a result of poor PM procedures, not leveraging defect-reduction upgrades, and setting equipment constants incorrectly.

Another cause of poor PM performance and high particles relates to matching issues on tools. In this example, software revision does not match across all tools. This, combined with incorrectly set equipment constants, may explain the high tool dedication, which in turn reduces the output of the fleet.

With a FabVantage 360 assessment, these calculations can be illustrated in a SEMI E10 Equipment States chart that shows the productive time of the tool and a breakdown of nonproductive time. As seen in figure 2, low throughput causes total tool productivity of only 63.6%, although the tool is utilized for 80% of the time. This example highlights a hidden opportunity to increase output by 25% by improving maintenance practices and equipment setup. Additional opportunities exist to reduce particles and defects, and improve process control with better FDC practices.

Figure 2. Example of a SEMI E10 Equipment States chart from a FabVantage 360 assessment which indicates that this fleet of four tools suffers from low productivity.

Conclusion

It is said that French artist Henri Matisse was notorious for spending extended periods of time looking at his paintings, reflecting on what he had done while plotting his next stroke. He would hold his paintbrush at a distance from the canvas and move it slowly through the air to try out different movements before committing to the next stroke on the canvas.[1]

Similarly, a FabVantage 360 evaluation provides customers with a “big picture” view of their fab situation, enabling them to plot their next “stroke” of improvement gains. The FabVantage 360 evaluation provides valuable data for use in prioritizing projects and quantifying ROI. It offers an easy, effective way to reveal how a customer’s tool performance and fab operations compare to the world’s best-in-class facilities.

For additional information, contact avi_edelstein@amat.com.

[1] Fred Mandell and Kathleen Jordon (2010). Becoming a Life Change Artist: 7 Creative Skills to Reinvent Yourself at Any Stage of Life. New York, NY: Penguin Avery Books. Can also be retrieved at https://books.google.com/ books?isbn=110144231X