Cleanroom workers use virtual reality training to reduce contamination
By Susan English-Seaton
Mesa, AZ — A “virtual fab” computer-based training course is now available for interactive training of semiconductor fab personnel in cleanroom protocols and wafer fab technology.
Modis Training Tech nologies has combined computer-based training (CBT) and Virtual Real- ity (VR) simulations in an integrated training package that can be delivered “on demand” through CD-ROM and the Internet. Based on CAD design and engine, the package includes four products: computer-based training (CBT), virtual reality, database tracking, and consulting. Using a database, rather than a task analysis approach, the course can be customized to company specs. Also included is a Courseware Management System, which tracks student performance and pinpoints specific areas for future modifications or improvements.
Level I, the introductory training product for orienting new employees, contains a “Clean Concepts” module which discusses rules and issues in cleanroom protocol and defines the differences between Class 1, Class 10 and Class 100 cleanrooms. It includes such topics as cleanroom concepts, types of contaminants, gowning procedures, and rules of behavior. The Advanced Semiconductor Training Package includes instruction in subject categories such as microelectronics, wafer inspection, and wafer handling. Level III, the virtual reality program, includes a “virtual reality fab walkthrough” with virtual simulations of the various bays — diffusion, photolithography, etch, nitride, poly, ion implant, CMP, and test.
Modis Training Technologies was started by Tom Orton and Scott Chamberlain in 1996. Starting out with Intel in 1970, Orton spent most of his time in cleanrooms, helping to build Intel factories in Oregon, Arizona and overseas. It was his experience in factory training — equipment repair, process training, and manufacturing training — that helped him develop a program which would allow trainees to operate machines and improve their skills without damaging wafers or the cleanroom environment via CBT and virtual reality simulations.
When Orton and Chamberlain started looking at the factory floor and how people were working, they found that, typically, out of 100 transactions, about 30 mistakes were made. “But to get to the die yield, the line yield, and the cycle time you really need in order to be able to sell a product competitively, you`ve got to get very close to zero errors.” Orton says. They decided to build a factory in the virtual world, making each piece of equipment interactive, so a worker could practice by running a simulation prior to operating the equipment in the real fab. “If you wanted to go in and learn how to run a Kokusi, an SVG vertical furnace, a Lam etcher or a Canon stepper, you go in and literally operate that machine.”
The advantages of remote simulated cleanroom training are not only obvious but are being borne out by some of the data collected so far, says Orton, based on results and a client list that includes IBM, Hyundai, Samsung, National Semicon- ductor, Sematech, and a training program for community colleges held in conjunction with Intel. “We`ve been able to find errors or problems within the factory — the specific defect densities and the CPKs that have been affected. Particle data we collected from a couple of the factories showed significant reductions.”
Another factor has been the need for continuous training. Orton and Cham berlain have discovered that typical behaviors in a cleanroom environment are forgotten over time. They recommend that initially, people practice going through cleanroom gowning, for example, as many as thirty to fifty times, then at the beginning of each week thereafter, repeat the virtual reality application and all of the process steps.
Besides reducing breakdown events because personnel have been virtually trained to perform their duties before operating the actual machine, the mere fact of not having to open a machine and expose it to the environment means less contamination. “One of the things we`re finding with these packages,” says Orton, “is that training reduces the engineering time on the floor, because there are not the mistakes being made. The derivative of the mistake is that there`s a request for the engineer. So the machine doesn`t go down as much either, because you`re not stressing the machine with the mistakes that are actually causing it to try and do something it`s not supposed to do anyway,” he says.
Modis training products are PC-based and run on Windows 95 or Windows NT and can also be configured to work on Apple Macintosh-based systems. For optimal performance, 32 M-bytes of memory and a Pentium workstation are recommended. With corporate offices in Mesa, AZ, Modis Training Technologies conducts business throughout the U.S., Asia, and Europe. The company`s World Wide Web site — http://www.modistt.com — provides on-line demonstrations and access to current product information.