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Advanced Service Collaboration—The Fab’s New Normal

Nanochip Staff

Faced with daunting semiconductor manufacturing challenges, chipmakers increasingly collaborate with Applied Materials service experts to pinpoint and resolve high-value problems in their fabs.

Given the explosive growth in smartphones and mobility products, today chipmakers have relentless cost- and cycle-time pressures, whether they’re building state-of-the-art microprocessors, NAND devices, or MEMS and power chips. Their manufacturing mandate is for equipment services that are more insightful, capable, and designed to forestall problems that can impact tool productivity and line yield. For example, as semiconductor companies moved beyond 28nm design rules, many of them hit various technical walls, with edge die yield and chamber matching among the most challenging manufacturing-related problems.

When it comes to service, Frank Nading has seen a dramatic evolution over the last three decades. Whether it’s matching etch chamber performance, figuring out what’s causing scratching during the CMP steps, or some other critical issue, semiconductor industry services now go far beyond conventional equipment support practices.

"Chipmaking is so complex now, and the cost of production is staggering. More than ever, our customers ask for help to accelerate yield, reduce cost and improve productivity of their Applied tools and their fabs," Nading said. “So today, when Applied brings service to the fab, we bring technology."

Frank Nading, Applied Global Services (AGS) solutions architect

FROM DISCOVERY TO EXECUTION

Nading, who has spent nearly his entire career at Applied Materials, said his job as a solutions architect within Applied Global Services (AGS) is to work with customers to discover their particular challenges, then help shape service solutions that address their technical and economic situations.

"All fabs have problems," he noted. "Most customers do some level of service on their own. But sometimes there are tough problems—the kind that are costing them time, quality and money—that they need help to resolve. That’s what we try to do: help them solve problems faster and at an affordable cost."

The initial job of the solutions architect is the discovery process, or as Nading describes it, "engaging directly with the customer at a very high level to find out what the real problem is."

The next step is proposing a specific solution, a methodology for getting to the root cause of the problem. "We do an assessment and say to the customer ‘this is what you need to do to fix the issue.’" The solutions architect then works with the customer to determine the right blend of in-house and Applied Materials expertise to deliver the required solutions.

Execution is the final step: proving that the Applied Materials service team has the right mix of expert engineers and tools to solve the problem. "A key aspect of successful execution is setting expectations correctly, being specific about what the AGS team will deliver, and then delivering on those commitments," Nading said.

BENCHMARKING NEEDED

AGS Vice President and General Manager Charlie Pappis says his organization exists solely to enable customer success. "Increasingly, our job is to help customers fine-tune processes for optimum performance and manage on-board technology so they can predict and prevent problems before they impact device performance and yield."

Often, this starts with an important first step: benchmarking.

"Part of the fab service value we bring is benchmarking," Pappis said. “We look at what is best-in-class performance around the world—using aggregate data from hundreds or thousands of installed tools in a given class—then compare it with the customer’s tools. Most of the time there’s a significant gap.”

Nading said a customer may report that uptime on a certain toolset is 70%, while Applied’s own data may peg best-in-class at 85%. "That often initiates a good discussion about how the AGS team can work with the customer to improve uptime, throughput or yield," he said. AGS’s FabVantage Consulting Group is a team of highly specialized experts who work with customers to identify and resolve specific yield-, throughput- and other productivity problems. Helen Armer, senior director of services technology, manages the knowledge base within the FabVantage Group. Armer said many customers ask Applied Materials for benchmarking to see how their tool or fab performance aligns with standard performance against a large set of similar tools. "This benchmarking often initiates a larger FabVantage engagement with very precise goals and objectives. Customers can then use Applied services to achieve and maintain these improved performance levels via a more comprehensive services agreement," she said.

Pappis noted that besides tool control, cost competitiveness is driving an increased customer emphasis on factory utilization. "Factory utilization rates are rather strong right now. As these rates climb, new modules can become bottlenecks. However, often a percent increase in throughput for a certain toolset can result in a percent increase in the throughput for the overall fab. FabVantage assessments can uncover opportunities for improvements in these areas as well," he said.

Jeremy Read, AGS vice president of Services Marketing, noted that FabVantage consulting is a key component of Applied Performance Service and Managed Service contracts, which are based on preconfigured tool- or on-wafer results. "Over the last few years, an increasing number of customers at all technology nodes have engaged with us for this capability, recognizing that it helps them achieve their difficult device performance, yield and cost-reduction goals."

THE EVOLUTION OF SERVICES

Services in the chip industry have evolved in stages. First, the shift from the original break-fix model—where corrective maintenance, spares delivery and cost were paramount—to something more complex started when foundries and memory companies began focusing more on cost of ownership.

Armer said that today high-k/metal gates, FinFETs, double patterning, vertical NAND, and other technology challenges have driven chipmakers to partner more closely with Applied, using the company’s TechEdge Technology Services, a new class of advanced service offerings.

"These services rely on sophisticated data analysis techniques coupled with the capabilities of specially trained service engineers,” she said. “When integrated with benchmarking assessments, they can help customers better understand what’s going on with their tools and processes, and often uncover multiple opportunities for productivity improvements."

Read said that keeping tools within a tight on-wafer specification, and matching chambers across multiple tools, are high priorities at device makers. “One thing that goes across the board is the need to reduce process variability, although the amount of reduction depends on the process.

"Both of our outcome-based service offerings are intended to reduce process variability. With Applied Performance Service, the contract spec is based on wafer data gathered using UVA [univariate analysis] and MVA [multivariate analysis] along with metrology feedback. For Applied Managed Service, the contract spec is built on tool data using UVA and MVA and test structures," he added. "The results can be quite dramatic. For example, for one customer thickness non-uniformity on Applied Centura epi systems was cut by more than 50%." (See figure 1).

Figure 1. Reduced process variability is one outcome of Applied FabVantage offerings. At one fab, the FabVantage team was able to significantly improve process control on an Applied Centura Epi system by finding and correcting hardware issues and by optimizing the PM procedure.

 

Read noted that the complexity of today’s device manufacturing environments requires a wider range of service capabilities than ever before. "We’ve now evolved beyond what has been considered normal service deliverables—routine tool maintenance activity and tool performance services—adding those focused on helping customers achieve desired on-wafer results and specific device-performance characteristics. Through service agreements incorporating advanced analytical tools, we are able to offer measurable operational excellence in yield, output, cycle time, and other key metrics that help customers attain their business and technology goals," he said. (See figure 2.)

Figure 2. Applied Performance Service and Applied Managed Service agreements focus on achieving customer-defined device performance and on-wafer results using a variety of FabVantage consulting and TechEdge services.

DATA SHARING NEEDED

The proliferation of sensors, data analysis tools and modeling methods in the fab opens the door to new service offerings that go far beyond traditional maintenance practices. But they can’t perform without sharing of data and IP.

Pappis said "it’s hard to envision customers universally allowing access to their yield and parametric data, only because their business is based on the unique IP associated with the data. So we propose going in with UVA and MVA capabilities that are generic to a target module."

"There are more than 1,000 unique tool-types in Applied’s installed base. Although they are different, they share many design, process and performance similarities. By overlaying data, we can quickly identify potential problem areas," Armer said, noting that FabVantage has completed more than 180 projects and accumulated data collection plans for more than 650 tools since its inception in 2009.

AGS as a whole has about 3,000 customer engineers (CEs). Each year, a number of CEs are selected to undergo the training required to be TechEdge engineers, using software tools and models that run within the Applied E3 fab management platform. These TechEdge applications analyze data from a collection of priority sensors and supporting capabilities such as rapid diagnostics, variability reduction, chamber matching, and a growing number of other capabilities.

PMs STILL IMPORTANT

Tim Trudgeon, a director in the FabVantage group, said he has witnessed a dramatic change in the willingness of customers to engage with Applied Materials service teams. "I see a tremendous amount of collaboration, especially in FabVantage projects, to match chambers or reduce defects. Once customers understand that our people have the right expertise, they pull us in and make us part of their team."

Trudgeon, who joined Applied in 1999, said many of the TechEdge advanced services delivered by AGS require "a mix of people with a high-level statistical data analysis background as well as those with a solid understanding of the hardware and the semiconductor fab. We want to be sure that the direction of the statistical analysis is correct. But it’s only when you combine that ability with people who understand how the tools work, how the process works, and the flow of manufacturing, that you get significant results."

And yes, that trained CE plays a key role. Matching the performance of a fab’s etch tools across multiple chambers involves many factors. A FabVantage team may identify the variables to keep chambers matched, with well-qualified maintenance people playing a key role. "It is really important to do a PM [preventive maintenance] properly, and PM routines at 20nm are much different than at 65nm. We have got to connect all the dots from a maintenance perspective to sustain that tool and chamber matching for a long time," Trudgeon said.

"We are trying to move our whole service business upstream. Instead of a model about how we meet a certain uptime metric, which is a tactical goal, we increasingly are helping customers meet strategic targets for end results such as on-wafer performance," he added.

Trudgeon said a FabVantage team just concluded a chamber-matching engagement that has led to a longer-term service agreement with the customer. The FabVantage team identified key variables contributing to etch CD variation, and suggested a series of fixes to the tool setup. "We provided the analytical ability to monitor the sensors on the components that matter. Everyone has FDC [fault detection and classification], but not everyone has the deep understanding of the equipment needed to know which sensors and components matter, and what are the appropriate statistics to apply to those sensors."

Once the FabVantage team determined which components tended to drift, the next step was working with the customer to develop a maintenance program "so that the chamber matching is sustained over time. This kind of analysis and advanced service has proven to be a big draw from our advanced-node customers," Trudgeon said.

DR. WATSON, I PRESUME

In that sense, the semiconductor service business isn’t much different from many industries, where human professionals are supported by computers and knowledge databases. Physicians, for example, draw upon knowledge databases to augment their own diagnostic skills. And who can forget the pounding that two human contestants took on the JEOPARDY! game show at the hands of IBM’s mammoth Watson supercomputer?[1]

Applied Materials is building its own Watson-like abilities to find answers for customers—ideally before problems become manifest. TechEdge services can be deployed to meet the key performance indicators in a particular service contract, Trudgeon said. Depending on the goals within a service contract, TechEdge engineers might prioritize certain sensors on a tool and develop the appropriate statistical analysis, pulling sensor trace data into Applied E3 at regular intervals or in real time, as needed. Priority sensors would be compared to proven models to better understand when there might be a component failure, the goal being to reduce scheduled downtime and better plan maintenance events.

"If the KPI is etch chamber matching, we would use TechEdge services to monitor and control when the tool needs to be maintained, for example," Trudgeon said.

"With TechEdge and FabVantage capabilities, we are building a very broad understanding about what goes on in fabs. We know a lot about how the elephants are running, and that makes us much better equipped to help solve customer challenges faster," Nading said.

Asked to conclude where Applied’s service business is today, he replied: "I think it’s evolving. And that service that may not have been a fit for you last year, well, now you should look again because it’s constantly changing. I like to think we’re getting better all the time."

Pappis summed it up this way: "To think that fabs can do it on their own is probably not true, and to think the OEMs can do it on their own is probably not true. It has to happen together."

For additional information, contact nanochip_editor@amat.com

[1] JEOPARDY! is produced by Sony Pictures Television, and is broadcast in 29 countries outside the U.S. http://www.nytimes.com/2011/02/17/science/17jeopardywatson.html?pagewanted=all&_r=0