Thirty-Five Years of SEMI Standards
By Robert Scace
SEMI, our favorite industry association, was three years old in 1973 and silicon was in short supply. Over 2000 different user specifications for silicon wafers existed. If a wafer failed to meet a given specification it had almost no chance of meeting any other specification, and was scrapped. Wafer manufacturing tools had to be re-adjusted continually from one order to the next, causing lost time and raising costs. Semiconductor device makers and their suppliers were opposed to the idea of standards, because they would need to reveal “proprietary” information to one another. At least they thought it was proprietary. But if your customer is running out of silicon, you may be running out of business.
Believing that standardizing some of the dimensions of wafers would lead to more efficient use of the available silicon supply, several wafer suppliers convened a wafer standardization meeting under SEMI oversight on May 4, 1973 to see if wafer standards might be acceptable. By the time lunch was over, a draft existed for 2-inch and 3-inch wafer dimensions based on customer preferences. A second meeting was held later in the month, and a third in October. By the fourth meeting, in February, 1974, between 80 and 85 percent of wafers then being shipped conformed to the draft standards for 2-in. and 3-in. wafers. The meeting overwhelmingly endorsed the draft specifications, and SEMI was in the standards business.
SEMI Standards Committee Formed
At SEMICON West in May of 1975 the committee was reorganized as a policy and oversight committee, the “SEMI Standards Committee”, with standards-writing activities moved to several new subcommittees: Silicon Wafer, Silicon on Sapphire, Packaging, Photoprocessing, Equipment, Wafer Carriers, and Chemicals. By June of 1976 a Memorandum of Understanding between ASTM and SEMI was signed by both sides. In July a set of standards by-laws (all two pages of it) appeared. The process was developing rapidly.
It had to. While there were wafer carriers then, wafers were all handled manually, one at a time, with tweezers. Carriers just let them be carried around more easily. But it eventually became clear that standard wafers and standard carriers would allow development of better ways.
Book of SEMI Standards Appears in 1978
The first annual Book of SEMI Standards appeared in 1978 as a loose-leaf publication printed on acid-proof paper, for convenient use in the fab. (Fabs were very different then.) It had three SEMI standards in it, backed up by a number of ASTM measurement standards and photos of all the participants.
International Standards Efforts
The next issue was to bring the Standards Program to Europe and Japan. Supplier companies and a growing number of semiconductor device companies were becoming active in the program, the large majority from the US. An increasing few came from Europe and Japan. How could the program be brought to them? Outreach was the best approach, but it needed to come with local support in those places to be effective. SEMI had no offices abroad, though there were local committees to organize the SEMICON shows. The whole organization had to grow.
In 1981 at SEMICON Europa in March, a European standards “chapter” was formed to develop a Standards Program in Europe. And to round out a year of early international exploration, the first SEMICON Japan occurred in Tokyo and the first ASTM/DIN/JEIDA/SEMI meeting was held to discuss silicon wafer topics. (Both celebrated 25 years of continued activity in 2006, still going strong.) An initial European standards organizational meeting was held during SEMICON Europa 1983. While attendance was good, the audience was not persuaded that SEMI could make important contributions to the standards needed by the industry.
SEMI Japan opened a Tokyo office in 1985. SEMI, in cooperation with JEIDA, distributed draft revisions of SEMI Equipment Communication Standards SECS-I and SECS-II in Japanese at a technical program co-hosted by JEIDA in Tokyo.
By the end of 1985 the SEMI Standards Program had accomplished several important steps:
1. Established itself securely in North America as a producer of standards of value to its industry.
2. Built strong personal and institutional connections in both Europe and Japan, building on visibility and contacts from SEMI exhibitions and other programs.
3. Established strong credibility with ASTM and good relations with JEIDA.
At SEMICON Europa 86, seventy people gathered to hear about SEMI standards and the potential value of their participation. This time the sentiment was more positive than in 1983, and an action plan was established to have a program in Europe ready to go by the next spring.
The Japanese versions of SECS-I and SECS-II were published in 1986 by SEMI Japan, which went on to establish STEP/Japan, a seminar series to discuss SEMI standards and local user requirements. This was a key educational move, which culminated in December with a large meeting during SEMICON Japan at which a Standards Program was organized, leaders were identified and actual work began. Some of the key Japanese participants had been involved with North American members in organizing the technical sessions that had taken place since 1981 during SEMICON Japan. The personal relations developed over these five years helped to put a solid foundation under the start of standards work in Japan.
The European standards start-up meeting at SEMICON Europa 87 in March marked a cautious beginning. With this started, an International Regulations task force, with a US chairman and two members representing Japan and Europe, was appointed to develop by February 1988 new Regulations to manage an international program.
1988 began with SEMI changing its name to Semiconductor Equipment and Materials INTERNATIONAL. At SEMICON West, the Board of Directors elected their first European and Japanese members. The International Regulations task force met its revision deadline and submitted the new Regulations to the Standards Committee, which adopted them. This act transformed the Standards Committee into the International Standards Committee (ISC). The Standards program now had firm footing on the three continents most active in the semiconductor industry.
SEMI opened a European office in Brussels in 1989 which, among other activities, provided the local support needed for building the standards base in the EC.
SEMI + SEMATECH
Further significant support for the Standards Program came from SEMATECH, founded in 1987 as a captive R&D operation by the major US semiconductor device makers. As its programs evolved, SEMATECH’s activity in SEMI standards work grew to be significant by 1990. This was particularly helpful because SEMI’s member companies are suppliers to the device makers and most of the SEMATECH participants in the Standards Program were from the supplier side. The device point of view is important in developing standards that are equally acceptable to both suppliers and their customers. Similar organizations were created in both Europe and Japan in this time period, improving the supplier-user balance there as well.
Now that SEMI standards were being developed by the various regions, many questions arose. Since just about all SEMI standards up to this time had been developed in the U.S., did the North American committees own them? Suppose “we” (Europe or Japan) see a need to revise one? Whom do we ask? Or do we just do it? And who repairs the relationships if someone makes the wrong choices? In spite of these questions, the first standards for flat panel display substrates were successfully developed and published, a joint Japan-North America accomplishment.
Time Capsule: Internet users top 100,000 in 1990. E-mail is not in general use worldwide. Letter ballots are conducted by “snail mail”. Better communication is coming, and is badly needed
These questions began to be noticeable by 1991, requiring re-thinking about how the SEMI standards process could become better integrated internationally. Starting with the annual planning meeting, attended by standards leaders from the three regions, we explored how to cooperate, how to collaborate, how to understand the way each culture thinks and works. Three days were not nearly enough. Regardless of the fact that we all were at least acquainted if not long-time friends, we still didn’t understand these issues well enough.
Book of SEMI Standards in Japanese
By year’s end, Japan successfully completed the approval process on thirteen new standards. In 1992 they handled thirteen more, and published the Book of SEMI Standards in Japanese. By 1994, Europe had produced ten. But the regions were operating independently, for the most part. Although standards members from other regions attended the larger SEMI exhibitions in (then) Geneva, Makuhari, and San Francisco, and worked together in many standards meetings, each standard had a tie to the region in which it was developed. Revisions were originated and taken to ballot from the home region, though all were SEMI International Standards and published in the Book of SEMI Standards.
Other industry events have furthered the growth and the necessity of the Standards Program. The creation of the (U.S.) National Technology Roadmap for Semiconductors in 1992 was fostered by the National Advisory Committee on Semiconductors in collaboration with the Office of Science and Technology Policy of the US government. The Semiconductor Industry Association (SIA) played a major role in supporting this action. It evolved into the biennial International Technology Roadmap for Semiconductors, first produced by the SIA and four counterpart organizations in Europe, Korea, Japan, and Taiwan in 1998. These detailed views of the future directions of the technology are valuable guides to needs for specific new standards or revisions of existing ones.
The level of cooperation and trust has continued to grow, step by step, until most of the regional differences have disappeared. This was greatly helped by the Procedure Guide, which details the every-day ways to conduct meetings, to develop standards, and to collaborate. It was first issued in December 2002 after a year of hard work by volunteers and SEMI staff. Now, in 2008, informal e-mails, international phone conferences, frequent and rapid distributions of draft documents, and electronic ballots have been commonplace for long enough that one tends to forget how long the evolution of this international process has taken.
There are now over 1,800 registered individuals in the Program, representing more than 880 companies and organizations in 36 countries. Nearly 800 SEMI Standards and Safety Guidelines exist, with more coming as needed. And they come by e-mail, internet, and CD.
Today the SEMI International Standards Program is in the late stages of acquiring certification by the American National Standards Institute, the US member body to ISO and IEC. It has been granted formal liaison with IEC TC 113 on Nanotechnologies. SEMI standards are accepted and used worldwide. Essentially every tool in every semiconductor fab conforms to SEMI Standards. In a recent closed international workshop at NIST on the needs for documentary standards in nanotechnology, SEMI was accepted without question as a significant player and peer among those present: the national metrology laboratories of Canada, France, Germany, Great Britain, Japan, India, Korea, South Africa, Taiwan, and the US; ANSI, ASTM, IEC, IEEE, ISO, OECD, and VAMAS.
The thirty-five years of SEMI Standards have been applied well. Congratulations!
About the Author
Robert "Bob" Scace has been an active leader in the SEMI Standards Program since 1975, as a founding member of the original Standards Committee and its successor the ISC until the present, as the chair of the ISC Regulations Subcommittee from its inception through 2006, and as the "corporate memory" of the SEMI Standards Program. Now retired from NIST, he represents SEMI as a US expert in ISO TC 229 and IEC TC 113 on nanotechnologies.