Wider 'Net-based tool diagnosis is becoming a remote possibility

Led by International Sematech, the semiconductor industry is moving rapidly to establish guidelines for the remote monitoring and repair of fab equipment using the Internet. The goals of the so-called e-Diagnostics program are to increase the availability of production tools, reduce the mean-time-to-repair rate, and significantly lower the costs of servicing equipment in the field.

Launched in spring 2000, the effort sets out to redress one of the ironies of the Internet age: the industry that makes the devices essential to operating the global computer network has yet to take full advantage of the 'Net's capabilities. Sematech cites at least four reasons for this reluctance. Those concerns center on security of data, lack of standards, and inadequate supplier support. Loss of intellectual property is another issue. Participants in the effort to establish an e-Diagnostics infrastructure hope to have solutions in place soon.

Currently, Sematech proposes an infrastructure that will operate on up to five levels of capability:

Figures presented by Michael Splinter, senior vice president and general manager of Intel's technology and manufacturing group, indicate what's at stake for chipmakers. Each hour of downtime can cost a fab as much as $100,000 in lost revenue, the executive said at SEMI's Industry Strategy Symposium in January 2000. A fab that reduces downtime by 1% on 50 of its most critical pieces of equipment has the potential to save close to $100 million annually. AvantCom Network, a supplier of Internet-based diagnostics software, cites industry statistics showing fab equipment experiences at least 8% unscheduled downtime and another 7% scheduled downtime.

In a technical presentation at Semicon Taiwan 2000, Chris Saso, AvantCom's technical sales manager, asserted that a typical critical tool failure, involving notification and gowning up, takes 11 hours from the initial alarm to repair. The total cost to bring the tool back on-line is $1.1 million. Automatic network reporting, in contrast, takes 8­9 hours from alarm to repair at a cost of approximately $800,000 to $900,000, a savings of $300,000 or so for each critical failure.

"We're moving at Internet speed on this," cracks Harvey Wohlwend, program manager for e-Diagnostics at International Sematech. "We think we're going pretty quickly. It's a unique project in that there's very wide industry collaboration on this and very active support in the supplier community."

Wohlwend leads the core team overseeing the implementation effort. The team holds teleconferences every Thursday. Seven working groups composed of Sematech members, other chipmakers, and suppliers have divided the areas of coverage. The e-Diagnostics teams cover network bandwidth requirements, capability taxonomy, data taxonomy, single-wire resolution, protocol definition, the data security model, and IT security. The working groups include representatives from suppliers such as KLA-Tencor, AvantCom Networks, Applied Materials, Nikon, TEL, Axcelis Technologies, and Schlumberger.

The industry has asked Wohlwend and his teams to move quickly, he acknowledges. Participants met most recently during Semicon Japan 2000 in early December and established a new working group that will define "an implementation roadmap for the industry," he says. The first meeting of the group had been set for mid-December.

The meeting in Japan was the first confab not hosted solely by International Sematech, Wohlwend notes. A combination of people, including Selete and SEMI, held the meeting, which revealed that the Japanese differ in their outlook on e-Diagnostics, he says. "Their approach was a little different. We started out with an e-Diagnostics approach, which is a subset of e-Manufacturing. Over time we envisioned ourselves growing into e-Manufacturing. Theirs is a kind of top-down approach. It's top-down versus bottom-up. We're committed to meeting in the middle, I guess."

Asked whether there's a direct yield- related or defect-related component to the effort thus far, Wohlwend called any such benefit "a stretch at this point. What we've done is limit the scope to not include those topics. We do not include APC [advanced process control] at this time. As one looks at the crystal ball, we'll probably grow it to e-Manufacturing and somewhere along the line pick up advanced process control."

Security--the most important matter of concern to chipmakers--is being addressed through several initiatives, Wohlwend points out. In particular, Sematech member companies have formed an IT security office. They've "actually completed a set of security guidelines that need to be followed...a lot of things like firewalls and encryption, as well as the practices that go with them."

Several companies are forging ahead in their efforts to find acceptable e-Diagnostics solutions in what Saso calls "this diagnostic wave that's sweeping over the industry." In December ASM Lithography and AvantCom launched a pilot project that will link ASML's demonstration lab in Tempe, AZ, with the company's headquarters in Veldhoven, Netherlands. AvantCom is providing the infrastructure that will enable the lithography system manufacturer to connect multiple equipment.

AvantCom already has a project in place with IBM's fab in Burlington, VT. Begun just after Semicon West 2000, that project involves etch tools from four different suppliers, says Saso. The chipmaker "is looking for solutions for its next-generation fabs. It has to make a decision as to how e-Diagnostics is going to work in their infrastructure."

AvantCom's mission is to provide a secure pipeline for its semiconductor industry clients, says Saso. The sales manager agrees that security shares the spotlight with protection of intellectual property as two major stumbling blocks. He identifies three different types of data. "There is data on the tool, obviously the fab recipes and things to make the wafer the way they want to make it," adding that the chipmaker could choose whether to give the tool supplier some form of license to use such data. "On the opposite end" there are algorithms, for example, covering deposition layers. Finally, there's a "gray area that's data created by the equipment but not necessarily recipes; how many times a robot moves, for example.

"The tack we are taking is that these data belong to the factory because they're within the factory walls," Saso explains. "We basically say, 'Hey, the factory and you are going to have to decide how you're going to use the information.' We've found that fabs are willing to share the data if the supplier will sign up to do something with it." The tool supplier using AvantCom's pipeline might sell the chipmaker on the benefits of sharing the data by promising "a high-percentage improvement in productivity," Saso suggests.

When AvantCom first became involved in the e-Diagnostics program with Sematech, "member companies wanted to reduce the cost of ownership of a tool by two-thirds," Saso recalls. "That was a very aggressive reduction in our opinion." He believes chipmakers now are comfortable with a more realistic cost-of-ownership reduction in the range of 25 to 33%.

The 1999 International Technology Roadmap for Semiconductors points out that "80% of the time is spent simply diagnosing the problem once a tool goes down," says Saso. Two issues stand out. One, the tools are complex, and two, "the knowledgeable expert is not at the tool. We're saying, let's address these two issues--how to get more information about the tools, and see if we can get somebody to remotely access the tool and help the field service guy."

FUTURE SHOCK: By cutting repair times, e-Diagnostics could help chipmakers meet ITRS equipment productivity targets and the implementation of the Roadmap's 300-mm software interface standards, says International Sematech.

Connectivity is the main reason ASML is working on the project with AvantCom, says Gerard de Zwart, vice president of global customer support engineering for the lithography system manufacturer. "Connectivity as an enabler of future improvements of the ASML service model, such as remote diagnostics, is considered of strategic importance. AvantCom has so far shown it understands the needs of both suppliers and IC manufacturers well and has the potential for becoming one of the major suppliers of connectivity or e-services."

Whether the pilot project is successful or not depends on several criteria, "ranging from product performance to service levels," says de Zwart. As for important fab data, "ASML considers any customer data we are allowed to use as very confidential, with access within ASML on a strict need-to-know basis. During the pilot, encryption and security during transport and storage are very important. Authentication and access control to the AvantCom products will also be tested."

The ASML executive points out that the lithography tool "is probably the most complex piece of equipment in the IC production process. It's influenced by many parameters, ranging from ambient pressure and temperature to the human operator. Some of these factors can be measured and used for diagnostic purposes, others have to be estimated or eliminated. Network-based diagnostics can surely help to get much better control of machine performance."

AvantCom backs one of two approaches to real-time network diagnostics. Saso says some tool suppliers already support so-called point-to-point network diagnostics, where each vendor's office is connected to individual process tools at the fab. AvantCom supports the central clearinghouse model, which provides a single point of entry to the chip plant and a secure central hub for access or routing of data to authorized parties.

"It's early days yet, and if I were to speculate I'd say it might be both methods that will be used," says Wohlwend. He believes that smaller equipment firms probably don't have the resources to implement point-to-point diagnostics and may opt for the clearinghouse approach. Bigger tool vendors, having sufficient bandwidth capabilities and dedicated lines, may have the resources to support the point-to-point solution.

"Already there are at least 10 suppliers in this [market] space," notes the program manager. "Some will be third-party software companies doing clearinghouse work or automatic data collection. This gets you into the world of APC and sensors. It's certainly fertile soil."

Indeed. Touting it as "a major step for 300-mm IC manufacturers," a company in Austin, TX, announced in early December its first enabling system for support of e-Diagnostics "at the tool level." DomainLogix's OBEM XP supports the traditional 20-year-old SECS/GEM interface. New standards such as OBEM, the SEMI E98 object-based equipment model, were written "to provide a way to describe the composition and behavior of complex equipment in a generic way and to support...advanced technologies such as APC and predictive maintenance," says Margaret Pratt, the standard's author.

The supplier says OBEM XP gives suppliers a standardized method of receiving data and reducing the time needed to detect critical failures, something that the existing SECS/GEM capabilities cannot do.