Issue



Japanese consortium SELETE reports on evaluation in progress


02/01/2000







While market conditions have improved enough to give some chipmakers confidence to move ahead with plans for 300mm operations, the Japanese consortium evaluating 300mm tooling says there are still a number of hurdles to be overcome before a complete, production-worthy toolset will be available.

Yokohama-based SELETE (Semiconductor Leading Edge Technologies), recently held its semi-annual progress report meeting in Tokyo to update its members on the status of the program, the first phase of which is expected to come to a close on March 31. By that date, the consortium plans to have completed evaluations of 128 tools. To date, approximately 60-70 tools have been evaluated.

The good news is that most 300mm equipment has reached or is close to 200mm tool performance, according to SELETE evaluation results. However, the cost of a 300mm wafer is still more than six times higher than the price of a 200mm wafer, well above the consensus 2.25x target. SELETE recognizes that price reductions will be realized once volume 300mm wafer consumption begins.

Moreover, SELETE said CMP systems and plasma etchers are still lagging in process quality. The consortium's evaluation team noted that there are also several issues in the "to-be-solved" category for a number of currently available 300mm systems. They include:

  • throughput of wafer steppers;
  • CD control of poly Si etchers;
  • selective ratio of metal etchers;
  • particles and metallic contamination of LP/AP/HDP CVD;
  • gap-filling uniformity of HDP CVD;
  • reproducibility of PECVD and spin coaters;
  • wet bench particulate control; and
  • whole-wafer CMP polishing uniformity and CMP consumable costs.

The quality of polished bulk wafers in terms of particles, metallics, COPs (crystal originated pits), and flatness is almost satisfactory, however particulate problems still exist for epitaxial wafers.

All this comes as somewhat of a mixed bag for those chipmakers who have decided to move forward with 300mm projects. Most recently, Hitachi signed up for a 300mm joint venture with Taiwan foundry UMC Group. Plans call for the venture to begin next month with an initial investment of 70 billion yen (about US$689 million). The operation will be owned 60% by Hitachi and 40% by UMC. Under the project, the firms will build a 300mm wafer processing mini-line at Hitachi's Facility N3, located at Hitachi's Naka Plant in Hitachi-Naka City, Ibaraki Prefecture. The line will occupy 6000 sq. meters of floor space, and the N3 facility has room for future miniline additions. Pilot operations are slated to begin in February, 2001, with full operations following in April, 2001. The line will have a production capacity of 7000 300mm wafers/month, with total capacity being split evenly between Hitachi and UMC.

The name of the new firm has not been established; the president will be chosen from Hitachi.

Meanwhile, Taiwan Semiconductor Manufacturing Co. broke ground on its planned US$2 billion 300mm fab, to be known as Fab 12, in the Hsinchu Science-Based Park. Production is scheduled to begin in early 2002. The fab is expected to be finished by the end of this year, followed by equipment installation in 2001. Fab 12 will pilot run with 0.15/0.13 micron process technology, and then evolve to 0.1 micron. Total capacity will reach 25,000, 300mm wafers/month. Some additional Fab 12 capacity will be reserved for R&D of 0.1 micron and beyond process development.

At SELETE, phase II (named the 130nm/300mm program) will begin in April under a two-year project at the consortium's Manufacturing Technology Research Department. Aside from 300mm equipment evaluation, SELETE has conducted three basic research projects at its Advanced Technology Research Department:

  • argon fluoride (ArF) lithography,
  • electron beam direct writing lithography, and
  • technology computer aided design (TCAD).

To date, researchers have achieved ArF scanners with a NA of 0.6, resolution <=0.13µm L/S (line and space), DOF <=500nm at 160L/S, and CD at less than 40nm.

With e-beam lithography, the group has achieved resolution of 0.08µm L/S. The consortium has also developed a TCAD three-dimensional device process simulator and distributed the first version to member companies. Version 1.5 will be available in March, 2001.

SELETE's six major projects for FY2000 (April 2000-March 2001) will be:

  • 0.13 micron/300mm equipment evaluation with an emphasis on copper/ low-k processing;
  • production efficiency enhancement in fabs with an emphasis on high performance and low cost CIM;
  • next generation lithography beyond the 0.1 micron node;
  • 0.1 micron process technology with emphasis on new material deposition/etching;
  • next generation three-dimensional TCAD; and
  • PFC gas control/prevention/collection.

In an effort to continue the SELETE program beyond the current 300mm evaluation project, SELETE has been exploring potential 0.1 micron (and beyond) device/process research themes. Potential themes include lithography, metrology and process reliability.