News & Analysis
Sematech tips new 450-mm efforts, pitch standard
Mark LaPedus
6/30/2009 4:08 PM EDT
SAN JOSE, Calif. -- Despite the IC downturn, International Sematech insists that it is continuing to make progress on 450-mm tool technology, by announcing several new efforts in the arena.
In a presentation on Tuesday (June 30), the chip-making consortium said it is moving towards a ''virtual processing'' model in the arena, in which 450-mm R&D will take place within Sematech and other sites worldwide.
As part of the effort, the group has shipped 450-mm silicon wafers for R&D purposes, ordered various metrology tools and advanced its factory automation efforts.
On the standards front, Sematech (Albany, N.Y.) has also devised fab tool performance metrics for 450-mm, revised the ''pitch'' tool standard from 10- to 12-mm, and targeted a specific node for 450-mm machines. As expected, the group is targeting 450-mm ''demonstration'' tools for the 32-nm node and ''pilot tools'' at 22-nm.
As reported, Intel, TSMC and Samsung are separately pushing for the advent of 450-mm ''prototype'' fabs by 2012. Some believe 450-mm fabs will never happen, saying the R&D costs are too expensive.
Sematech is spearheading the 450-mm effort. The chip-making consortium has devised a 450-mm ''test bed'' in Austin, Texas. The ''test bed'' is located within an R&D fab once owned by Sematech. That facility was recently acquired by SVTC Technologies Inc., an R&D foundry.
Much of the 450-mm development work, especially in fab automation, continues at the ''test bed'' within the SVTC. To some degree, Sematech will be processing 450-mm wafers within the facility by the third quarter of 2009, said Tom Jefferson, 450-mm program manager at Sematech.
At present, though, there is still no CVD, etch, lithography and other critical gear for 450-mm processing. Sematech claims to be ''actively engaged'' with fab tool vendors in those segments.
Since the SVTC facility does not have many of the critical tools, Sematech is moving towards what it called a ''virtual processing'' model. The chip-making consortium will ship 450-mm test wafers to various sites and vendors worldwide for processing.
Still to be seen, however, is who will pay for the 450-mm R&D. A 450-mm fab is expected to cost $10 billion, some estimated. Scott Kramer, vice president of manufacturing at International Sematech, said R&D costs will be spread out among the member companies in the consortium, equipment suppliers and material makers. Kramer also dropped hints about a ''public'' entity, but he did not elaborate.
Standards, more standards
The subject of 450-mm technology remains a hot button in the industry. Several years ago, Sematech unveiled two next-generation fab programs: 300mmPrime and the International Sematech Manufacturing Initiative's ISMI 450mm effort.
There is widespread support among the fab-tool community for 300mmPrime, which looks to boost the efficiency of existing 300-mm fabs, thereby pushing out the need for 450-mm plants.
The newer, more controversial ISMI 450mm program, calls for some chip makers to make a more direct transition from 300-mm to the larger 450-mm wafer size.
In some cases, Sematech's unveiling of the controversial plan to hasten the industry's move to 450-mm wafers has driven a wedge between the semiconductor equipment community and some chip makers, rekindling the debate over who will fund the development of next-generation fab tools--or whether the shift should in fact proceed at all.
In 2007, Sematech announced plans to install a "factory integration test bed" facility for the development of 450-mm fab tools. The facility, to be located in Austin, could help propel the 450-mm era.
Last year, Intel, Samsung and TSMC reached an agreement on the need for industry collaboration for 450-mm technology starting in 2012. Meanwhile, after several competing proposals, Sematech, SEMI and the IC industry last year settled upon a wafer thickness standard of 925-micron, plus or minus 25-micron, for the so-called ''mechanical standard'' for 450-mm silicon wafers. In comparison, a 300-mm wafer has an overall thickness of 775-micron.
In the presentation on Friday, Sematech outlined its latest efforts in 450-mm:
1. The development of 450-mm silicon wafers. Previously, Sematech had only devised ''sintered'' wafers. But now, it is making single crystal wafers available to the industry. There is no change to wafer thickness standard.
2. The metrology story. Sematech has begun to order various metrology tools for 450-mm, such as particle inspection, edge inspection, film thickness and particle removal. Tools will be shipped by the second half of 2010. Sematech has recently selected a metrology tool from Creative Design Engineering Inc. (CDE). It has selected CDE's ResMap 575, a four-point probe resistivity mapping system.
3. Factory integration rolls. At one time, Sematech only had one equipment front-end module (EFEM) and one carrier in the ''test bed.'' Now it has four EFEMs, six loadports and multiple carriers. It is also testing a person guided vehicle (PGVs) for wafer transport.
4. More standards. It is also devising so-called equipment performance metrics for some 60 tool types. And it is moving forward with the carry-forward, opening method (latch key) standard; all other technologies have been dropped.
5. Hit or pitch. It has also revised its pitch standard for fab tools. There was a push for a 10-mm pitch standard for the wafer carriers and other tools. Now, that standard is 12-mm, which may reduce wafer warpage.



