I300I guides 300 mm transition
Austin, TX — The contamination control industry is bracing itself for the semiconductor industry`s conversion from 200 mm to 300 mm wafers.
This July, American and Japanese consortia will issue a document containing guidelines published by SEMI`s International 300 mm Initiative (I300I). The I300I document will set standards requirements and equipment designs for 300 mm wafer factories in the United States and Japan. With the implementation of factory automation in domestic and foreign fabs, all parties to the consortia recognize both the importance and the practicality of ensuring that process tools are equipped with properly designed, standardized factory automation interfaces to better utilize process tools and provide a better, cleaner environment.
The I300I document will include guidelines on carriers and interfaces for tool loading, definitions of equipment performance metrics targeting 0.25-micron technology for manufacturing starting in 1998, and test methods for member companies to guide evaluation activities.
I300I member companies — AMD, Hyundai, IBM, Intel, LG Semicon, Lucent Technologies, Motorola, Phillips, Samsung, Siemens, SGS-Thompson, Texas Instruments and TSMC — have already achieved several key milestones, according to Frank Robertson, I300I`s vice president and general manager. A set of guidelines on carriers and interfaces, reflecting a consensus model of tool loading in 300 mm fabs, identifies SEMI standards endorsed by I300I member companies for equipment compliance.
Asyst Automation Inc. (Austin, TX) is one such company that manufactures its front-opening interfaces in compliance with SEMI Draft Document 2502`s “Front Interface Mechanical Standard,” working directly with tool suppliers to integrate its front-opening unified pods and minienvironments into the tool. He says, “The guidelines have provided a lot of direction to the tool suppliers we interface with, and that`s extremely helpful to us. At one time, there was a possibility of eight different carrier options. Now that it`s been narrowed down to one — compatibility of open cassette with front-opening — it`s really made things a world easier!” claims Bill Fosnight, R&D 300 mm project manager for Asyst, working with Sematech.
Operating as a subsidiary of Sematech, I300I is a consortium of international device companies whose first task in 1997 is to evaluate equipment to coincide with 0.25-micron beta tools delivery in mid-1997. The switch from 0.25 micron to 0.18 micron is planned for mid-1998, when 0.18-micron technology will be evaluated for delivery of beta tools in mid-1998. The earliest manufacturing facilities for 0.18 micron will require delivery of production tools in mid-1999.
To support demonstration of equipment I300I has established a Process Support and Metrology Center in a Class 1 cleanroom in Austin, TX. The main objective: to accumulate data from single-unit evaluations performed by equipment suppliers of alpha and beta tools, primarily at suppliers` sites.
Finding IC makers unwilling to contribute to tool development costs, equipment companies are footing almost the entire cost. While device makers have formed consortia to generate data on 300 mm and track progress toward manufacturing capability, suppliers are focusing on the market as it evolves, timing investment relative to the payback through customer orders. Practically speaking, conversion will occur when 300 mm manufacturing capability is cost effective relative to 200 mm, says Robertson.
In Japan, the Japan Working Group (J300) combines the standards requirements and standards development, while Selete (Semiconductor Leading Edge Technologies, Inc.), a joint venture of Japan`s 10 top device manufacturers, has the mission of evaluating 300 mm equipment. SEMI has received the output of the joint review on standards requirements between I300I and J300, and I300I has also met regularly with Selete. In Europe, I300I and the European Community Semiconductor Equipment Assessment program have agreed to use the same metrics and methods and to share cost and results of cooperative demonstrations for 300 mm tools from European suppliers.
Equipment performance metrics have been defined by member companies for 24 tool types, based on factory cost and technology targets for 0.25-micron performance at manufacturing starts in 1998. A comprehensive set of demonstration test methods for generating data, which will be accepted by the member companies, has also been defined to guide evaluation activities. These documents have been delivered to global suppliers and other organizations and are posted on a World Wide Web site (http://www.i300i.org).
One of the first companies whose equipment meets I300I guidelines is PRI Automation, Inc. (Billerica, MA). Its Intra-Tool Buffering (ITB) tool automation system meets I300I`s new material-handling guidelines, buffering work-in-process (WIP) within process tools, loading and unloading wafer carriers to and from its 300 mm door-opening load port to ensure continuous wafer availability. “The main thing is that we`re really starting to adopt the principles of Standard Mechanical Interface (SMIF) technology, and we`re designing upfront in this new generation of equipment the capability to better handle that so the factory will perform better,” says PRI`s product manager for advanced automation systems, John Alexanderson.
Will the implementation of SMIF technology, including the integration of minienvironments into tools, signal a radical shift in the overall cleanroom classification? Asyst`s Fosnight says, not right away. “Most of the top-tier semiconductor suppliers are looking to maintain their level of cleanliness, and I think that`s done from a risk management standpoint. So I think they see closed carriers and the need to automate 300 mm as the key things to focus on now.”
PRI`s Alexanderson says, “I think what they`re sensing is that as we move into the larger wafers, and device sizes make the transition from 0.25 micron to 0.18 micron, I think they`re looking toward the future with at least the option of being able to handle wafers in a cleaner environment. They don`t necessarily see the need for it now. I guess you could say they`re building the infrastructure for future smaller device sizes.” Cleanrooms will have tools outfitted with minienvironment capability for the microenvironment carriers, but they will still maintain cleanrooms with Class 1 performance — both interbay and intrabay. Alexanderson says, “Eventually — and that`s pure speculation — you may see [cleanrooms] going from Class 1 to Class 10, but I don`t think you`re going to see the Class 1 to Class 1,000 type of transition.”