Who is doing what with supplier-to-fab e-diagnostics
09/01/2002
Solid State Technology's March 2001 e-diagnostics report found that IT technology for linking equipment suppliers to tools in fabs was available, but operations managers were concerned about IP and process-recipe security. Last year, most concepts involving e-diagnostics - whose official definition itself was just a year old - were still only PowerPoint presentations. One of the few, early, viable supplier-to-fab e-diagnostics programs in place was from KLA-Tencor. Its success with iSupport was exemplary, "resolving 25% of all support calls without on-site involvement, with dramatic reduction in MTTR."
Through 2Q02, KLA-Tencor (San Jose, CA) has implemented iSupport at 18 customer sites in the US, Europe, Taiwan, Japan, Singapore, and Korea, with >240 tools connected to on-line support. The software behind iSupport has been sold to Brooks-PRI Auto mation (Chelmsford, MA), which licenses it back to KLA-Tencor and has also packaged it into a broadly applicable industry standard solution called iConnect. In addition, KLA-Tencor has broadened its e-diagnostics effort into iPartner (see "Packaging e-diagnostics").
From iSupport to others
Today, there are still many PowerPoint presentations on how e-diagnostics should be done or work, the benefits, etc., and the industry standards are still evolving.
Alan Deeter, GM of the equipment engineering solutions business unit at Brooks-PRI, says, "After acquiring iSupport software, everyone wanted to know the ROI, but no one was ready. Then, there was a lull in interest. Today, we are seeing increased activity and a maturing market. Recent inquiries and pilots are more focused on capabilities, cost, and time to implement."
Compared to iSupport, iConnect has the ability to take data from both SECS and DDA ports, allowing rapid adoption and retrofitting without changing existing tool software. "We have also merged it with other software capabilities that bridge the functionality of other near-tool applications, specifically for fault detection, predictive maintenance, and equipment performance tracking," says Deeter.
In another e-diagnostics effort, Petar Maro evic, product marketing manager at Cymer (San Diego, CA), says, "In early 2001, when we initiated beta-testing of CymerOnLine, we were among the first suppliers to discuss with fab managers requirements for equipment networking and the benefits of remote data sharing. We weren't surprised to learn of the sometimes wide disparity between the promise of e-diagnostics and the reality of related fab IT policies and practices." CymerOnLine is a working e-diagnostics software solution for deep-UV excimer lasers used in production lithography (see "E-diagnostics in action: Watching DUV excimer lasers").
A market study that Cymer conducted earlier this year indicated that industry momentum had, in fact, slowed with respect to e-manufacturing. "It is probably an oversimplification to hold the economic slowdown solely responsible for this loss of momentum. The study also points to the unclear commercialization path for software solutions of this type, as well as known barriers related to fab IT integration and security," says Maroevic.
Despite the clamor for e-diagnostics, many equipment and materials suppliers are still moving cautiously. One fab manager tells Solid State Technology, "While suppliers have been saying that they have the technology ready to go, in most cases this is simply not the case. Many do have the vision, but they tend to be stuck in the business mode of trying to figure out how they are going to make money. Only a few are showing that they believe in the concept and are proceeding with doing it."
Indeed, Solid State Technology has found that a few equipment and materials suppliers have gone boldly ahead with implementations unique to an equipment set or materials supply (see table and "E-diagnosing ATE"). And there is significant e-diagnostics capability being developed at the sensor and subsystems level by suppliers such as Inficon (E. Syracuse, NY), Advanced Energy (Fort Collins, CO), MKS Instruments (Andover, MA), and others. For example, Inficon's capability is built around FabGuard software and integration that builds a fab tool's e-diagnostics information from sensors unique to a given system. In one fundamental example, FabGuard used with RGAs on a PVD tool results in a reduction of 120 hours of downtime per year, equating to a 1.4% improvement in raw tool utilization over the course of a year.
Joe Monkowski, senior VP of business development at Advanced Energy, says, "We realized several years ago the value of e-diagnostics and began working at that time with the Symphony product line to take advantage of the connectivity and data management infrastructure it offered. Today, we are connecting the Symphony products to our sensors and subsystems as well as to third-party sensors to permit us and our customers to monitor the performance of subsystems and process equipment in real time. This is being done at multiple end-users and OEMs."
From another angle, much of the progress with e-diagnostics seems to be driven by a few pioneering semiconductor manufacturers who are absolutely convinced that e-diagnostics is required for the future success of the industry.
At STMicroelectronics
Moving cautiously toward advanced process control and e-diagnostics, STMicroelectronics has connected CVD, PVD and etch tools in all eight of its 200mm fabs to the MKS IPC Products Blue Box, in a beta site evaluation. "We are concentrating on processes where there could be a quick payback because the potential for scrap wafers is highest," says Peter Gaboury, ST's equipment programs manager.
The Blue Box is a communications manager that fully supports SECS I, HSMS, and SECS II. It collects and displays process data at high speeds and integrates process equipment, hosts, and sensors. Based on standardized PC components, the Blue Box is compliant with Semi E04, E5, E30, and E37 and supports the International Sematech (ISMT) e-diagnostics initiative. Combined with the Tool & Wafer Fingerprinter application, the Blue Box provides an engineer with remote computer access to machine and process data on charts and spreadsheets from anywhere in the world via a web browser. Any host application can be connected to the Blue Box - via SECS, TCP/IP, or API - and use its automatic data collection capabilities.
While Blue Box connections do provide the eventual ability for equipment suppliers to access tools remotely in ST fabs, "We are not ready to open our tools because we are moving cautiously," says Gaboury. "But this is definitely a first step toward e-diagnostics because an equipment-supplier technician can sit in our offices with us and analyze data. We can stop a tool before it starts scrapping wafers. The actual value for e-diagnostics is going to be when we can start predicting potential failures and anticipating parts and maintenance needs ahead of time."
 |
null
E-fab to watch
Many are watching the ramp of IBM's 300mm fab in East Fishkill, NY. As you read this, it is ramping wafers where all tools (~300) will have an e-diagnostics link to their suppliers. IBM has publicly stated that it intends to lead the industry in e-diagnostics. The bi-directional high-speed communications expertise behind e-diagnostics being implemented at IBM's 300mm fab belongs to ILS Technology (Boca Raton, FL), tapping experience gained from automation projects that include three at Chrysler engine plants.
ILS has been actively involved in semiconductor applications for a decade and is part of a NIST-funded consortium with AMD (Sunnyvale, CA), Asyst Connectivity Technology (Austin, TX), and Oceana Sensors Technologies (Virginia Beach, VA). This group is investigating an object-oriented security framework that will use a "flexible security wrapper" for securing data in e-manufacturing. Briefly described, this project is developing security control by which equipment suppliers have increasingly broad access to equipment-specific fab data as a given problem situation grows in severity.
Describing the effort at IBM's 300mm fab, Rich Mason, president of ILS, said, "We are involved with implementing a system based on our e-Centre software that connects tool vendors with the fab for collaboration on continuously improving tool performance." e-Centre contains all IMST functionalities for security, authentication, session management, bus iness rules, file transfer, remote tool take-over, and other fundamental tasks. ServiceNet ties it all together for transmission in a highly secure manner, via the Internet." Mason says, "There is logic in our e-Centre server that customers tell us is pretty unique - things like data authorization, our business rules engine, or how, in a simple graphical manner, users can allow people to determine what data they do and don't see."
In operation, the ILS system transmits tool health-monitoring data to the appropriate supplier on a 24/7 basis. Upon review, an expert, located anywhere in the world, can begin a session with a fab engineer to further analyze data and tool files and, with permission, can take over remote tool control in real time. "This set-up is crucial for the industry getting a handle on equipment efficiency because equipment companies are certain they know how to improve tool performance," says Mason. What does the ILS approach add to the overall cost of a 300mm fab construction project? "It's minimal," says Mason.
Here comes e-diagnostics
"The e-diagnostics application space in our industry is sorting itself out at the moment," says Bill Ramus, ILS's VP of marketing. "IC manufacturers, equipment suppliers, and third party software providers have been simultaneously, and in some cases independently, creating solutions that may not be convergent and cost-effective for industry."
Dave Faulkner, executive VP at Cimetrix (Salt Lake City, UT), a company that has provided connectivity software for several tools in the IBM program, says, "Until the rest of the industry has a clear implementation plan for e-diagnostics, our advice is to make sure any purchased tools have multiple connection ports to facilitate eventual e-diagnostics plans and whatever the next new cost-effective host application may be."
Ramus adds, "It is equally important that OEMs and ICMs not develop IT infrastructures to provide for data security, data transmission, user authorization and authentication, remote collaboration, and other base framework capability for e-diagnostics."
Is, perhaps figuratively, everyone watching the IBM installation? Mason says, "The industry believes that e-diagnostics is absolutely necessary, its newness is being watched very closely. I can assure you that we are working actively with at least half of the top 10 OEMs in the industry."
Acknowledgments
iSupport and iConnect are trademarks of Brooks-PRI Automation Inc. iPartner is a trademark of KLA-Tencor Inc. PowerPoint is a registered trademark of Microsoft Corp. NxGenSupport is a service mark and NxGenConnect a trademark of NPTest. CymerOnLine is a trademark of Cymer Inc. eConnectNET is a trademark of Teradyne Inc. FabGuard is a trademark of Inficon.
Pete Burggraaf has more than 25 years of experience in the semiconductor industry, including work at Motorola, Siemens and ASM. He can be reached at 875. S. Yucca Dr., Wickenburg, AZ 85390; ph 928/682-1265, fax 928/441-3139, [email protected].
Packaging e-diagnostics
Typically, equipment support programs offered to the semiconductor industry focus on assigning sizable service teams at fabs. This approach is costly and inefficient because it requires a customer to pay for a level of support that is not constantly required.
KLA-Tencor's iPartner program leverages a combination of on-site and 24/7 online resources that a user selects. In operation, users with 24/7 online support work with KLA-Tencor online engineers to resolve common issues, reducing the need for on-site dispatch, reducing costs, and increasing tool uptime. When an on-site visit is needed for complex issues, KLA-Tencor online engineers diagnose the problem and identify and order necessary parts so the local support engineer arrives on-site ready to resolve the problem quickly. This reduces mean time to repair (MTTR), further cuts service costs, and increases tool uptime.
The iPartner program also addresses evolving manufacturing requirements. For example, a 300mm fab with highly complex inspection and metrology tools, and critical applications, requires a high level of support to ensure a timely ROI. For a mature 200mm fab, the tool set and applications are less critical so users can opt for a support package that lowers service cost. In addition, the program is designed to factor in changes in service and support requirements that occur as process and product cycles mature.
E-diagnostics in action: Watching DUV excimer lasers
An exposure tool is always in full operational control of its laser light source, but only a few critical parameters are monitored regularly. Parameters that pertain to the laser, module performance, and productivity must be monitored and archived to enable proactive maintenance and troubleshooting. While laser downtime is minor compared to overall lithography cell downtime, module-replacement costs do keep the overall cost of laser ownership relatively high.
Some fabs manually collect laser data several times a day for analysis, including parameters such as energy dose, spectral bandwidth, chamber voltage, and pressure. This allows some proactive maintenance, but downloading data manually from a diagnostics port requires cleanroom access and is very time-consuming.
The core of CymerOnLine is a data-acquisition system that automatically and periodically accesses - through the laser's RS232 port - every connected DUV laser in a lithography area, storing acquired data in a relational database. This connection uses industry-standard communication protocols and encryption algorithms with message authentication. Using an existing port, users do not have to open any additional ports in their firewall and do not need expensive virtual private networks. The user-interface and laser performance and diagnostic information can be accessed by any Web browser from anywhere.
The remote data sharing function allows customers to set up and store either automated or on-request secured data transfer to a predefined Cymer location. Each dataset is tagged by the customer's unique identification number to prevent the ex change of confidential data between customers. With this functionality, Cymer's customer service and support organization can reduce both the mean time to assist or repair lasers, as well as the learning time for supporting newer lasers.
The data collected from a laser consist of information about the quality of the produced light and information from the modules, which need to be tightly controlled to guarantee performance. For example, pulse energy and wavelength relate to the quality of the light; chamber voltage and pressure provide information on module status.
In the real world
At the heart of an excimer laser is a pressurized gas-filled reaction chamber ("gain generator"). To produce light with the correct output power and spectral characteristics when electrodes are energized, it is imperative that pressure, temperature, and gas concentrations in this reaction chamber be well controlled. The laser has built-in sensors and algorithms that automate this job. Every time a lithography system requires the laser to produce light, the laser automatically will assure that minimum chamber conditions are met. CymerOnLine can highlight chamber status before the laser begins firing, as well as what happens during the laser's idle status.
Recently, a user of CymerOnLine detected chamber pressure variation during laser idle time. Since the laser will automatically assure that minimum chamber conditions are met, this variation in chamber pressure would probably not have been detected using a different approach. The variation was traced back to a minuscule leak in the chamber, which was ultimately replaced.
To control chamber temperature, heaters and heat exchangers are installed in and around it. In another successful e-diagnostics case, a second user reported large fluctuations of laser bandwidth, frequently reaching 0.8pm, the point requiring maintenance. Often, high bandwidth spells the end-of-life for either the chamber or the laser's bandwidth-narrowing module. In this case, however, replacing the chamber did not solve the problem. The tool's e-diagnostics data indicated coincidental large variations in chamber temperature, which explained the fluctuation in bandwidth. Further investigation helped to determine that temperature fluctuations were caused by a mis-wired chamber heater. A simple, two-minute procedure corrected the wiring and prevented erroneous module repair or exchange and loss of production time.
Troubleshooting efficiency
In addition to pinpointing specific problems, Cymer OnLine can exclude a certain factor or system from a problem being analyzed. This speeds up troubleshooting. In a representative example, a lithography system was suspected to have a problem with scanner magnification drift - a problem where the laser is a potential contributor and was therefore included in the overall inspection. Graphing the associated data gathered via e-diagnostics showed, however, that the wavelength performance of the laser was well within specification; it was excluded from further troubleshooting of the complete system.
The energy stability of the laser - its ability to control the number of photons projected toward the photoresist - is extremely important. Generating light is a difficult process that requires many active control knobs to accurately meet output power and other spectral specifications. If a laser has a problem with energy stability, the laser's energy sigma measurement can increase. In one case, a particular laser exhibited a large fluctuation of energy sigma (Fig. 1). This particular example was traced to a communications problem between the scanner and the laser.
In some instances, laser energy might drop below a minimum, resulting in a shutdown. In a specific case, CymerOnLine graphing showed that a laser reported an instance when the energy dropped to 0μJ and the corresponding voltage reached a maximum. Lack of F2 gas or the aging of the chamber or optics would have resulted in a gradual decrease in energy vs. time. The graph displayed sudden spikes, however. The fact that the energy suddenly dropped to zero pointed to a power-supply problem. Indeed, after the second occurrence, it was discovered that the laser's power supply was malfunctioning.
DUV excimer lasers are pulsed lasers. In rare instances, a single laser pulse deviates from the target energy by as much as 30%, affecting beam quality. Cymer's e-diagnostic tool was specifically designed to handle situations when the energy of the laser occasionally drops below a threshold and to report a beam quality problem to the scanner. In such cases, most laser pulses are the right energy, but an occasional pulse is not. Since this occurs for as few as one pulse/100-300 pulses in a burst, the laser's energy sigma is not the right indicator of the problem. In the particular case, the Cymer tool analyzed the laser's shot database, indicating that the laser's minimum energy was indeed dropping near 5mJ, while all other parameters indicated no problems. It was determined that the energy-control configurables were not set properly.
Ultimate value
During the first year of field use for CymerOnLine, some key end-user benefits were successfully confirmed:
- Model-based data analysis of individual module performance enables more accurate module lifetime estimation in contrast to statistical forecasting based on historical performance data for all of the modules of the same type, thus reducing consumable cost.
- Providing timely light-beam performance information enables lithography engineers proactively to prevent or reduce product loss.
- Remote monitoring can be set up to enable fast, expert troubleshooting, as well as additional uptime and productivity improvements.
An easily overlooked benefit of the system is that it provides equipment and process engineers with a new way to look at laser performance. Often, this new view triggers ideas on how to further improve or optimize production or maintenance. In addition to chipmakers, equipment manufacturers can also benefit. Our internal studies, for example, indicate that user support can increase productivity by using the system.
Petar Maroevic, Emiel Thijssen, Parthiv Patel, Cymer Inc., San Diego, California
E-diagnosing ATE
On the equipment supplier side, e-diagnostics does seem to be emerging fastest with ATE suppliers, perhaps because the process overhead is largely electronic and software based, without too many elements of electro-mechanics, process chemistry, recipes, the kinds of overheads and complexities associated with etchers, deposition systems, etc.
For example, Teradyne has begun offering e-diagnostics via its eConnectNET integrated into a set of new services packages; eConnectNET, which several users are trialing as part of 24/7 service, is built on iConnect licensed from Brooks-PRI. Teradyne chose iConnect because it satisfies the security requirements of ISMT. Greg Tobin, marketing manager for Teradyne's Global Customer Services Division, says, "We see e-diagnostics as an important part of our next-generation services model to provide both maintenance and applications support. What we have put in place can provide users with 24/7 service at an unprecedented cost."
While eConnectNET can bring users faster response and problem resolution from Teradyne, it can also be used to connect securely with a user's business partners. "For example, a sub-contractor production facility could connect with device designers," says Tobin, "whether they are fabless or an IDM. This helps to reduce travel and accelerates the process of porting applications into production."
In another ATE example, NPTest (San Jose, CA, formerly Schlumberger Semiconductor Solutions) has integrated its e-diagnostics solution NxGenSupport using its NxGenConnect service technology. Currently providing level 0 and 1 support, NxGenConnect is running at wafer sort and package test facilities.
Chris Stambaugh, director of technology development for customer service at NPTest, says, "Right now we are focusing on three key customers and have about 50 test cells connected. But there are hundreds more test cells in customer's facilities and our goal is to bring immediate impact by improving OEE on these legacy systems. NexGenSupport is focused on difficult problems where tools typically are out of production for hours or days, or situations where the tool can be brought back on-line but the root cause is not really solved."
NexGenConnect leverages Schlumberger core technologies in information security that it uses in other industries, including secure connectivity centers, SmartCard technology, and digital certificates. NxGenConnect uses industry-accepted protocols for its security, connectivity, and strong encryption. In addition, it supports two-factor authentication and requires only a single outbound port on the customer firewall.
From the test cell, the customer product engineer or technician double clicks an icon and securely accesses the NxGenConnect server. Once credentials are authenticated, certain applications are available based on the user's roles within the NxGenConnect server. Likewise, any other authorized customer, partner, or NPTest employee can securely join a NxGenSupport session from any business-neutral location in the world. The user in the test cell always retains control of the session and can give remote experts the capability they need to analyze, debug, and resolve an issue.
By Pete Burggraaf