by Debra Vogler, Instant Insight Inc., Sunnyvale, CA
The announcement of EV Group’s 450mm patterned wafer at last year’s SEMICON West unleashed even louder debate on the economic need for 450mm manufacturing. With more equipment suppliers announcing 450mm efforts, and a long list of research consortia dedicated to developing 450mm, it does seem as though the industry is clearly aiming for the finish line. While some are providing definite commitment dates, there are also those issuing words of caution.
Suppliers on the 450mm Bandwagon
Thomas Glinsner, director, product management, at EV Group, reports that the company is part of a number of European-funded projects (see Fig. 1) including: EEMI450, SOI450, NGC450, and EEM450PR. Still another project – in the discussion phase as of this writing – is KET-Eol.
Figure 1. Overview of European funded R&D projects (450mm). SOURCE: EEMI450 Initiative
The company still stands by its estimate for 450mm HVM insertion as somewhere between 2015 and 2017. Realizing that there will be a much smaller number of end users for 450mm manufacturing, “EVG wants to be ready for 450mm processing as soon as the foundries and IDMs are ready to make the transition,” said Glinsner. In fact, the company wants to be early in the game. “That’s why we’ve developed the 850SOI bonding system. SOI wafers might play a big role beyond 20nm, and we want to be a part of that, so we decided that this would be the first equipment we would build on a 450mm platform.”
Ultratech is also enabling 450mm manufacturing by working with SEMATECH and with large IDMs and foundries to understand the timelines. “Ultratech’s position is that it will have the equipment available to transition to 450mm,” noted Scott Zafiropoulo, VP of marketing at Ultratech. The company is using a two-phase approach to develop 450mm tools for both packaging and laser spike annealing applications. For either product development effort, the company will first scale-up the tool itself, and once proven, the second phase will tackle productivity improvements.
According to Manish Ranjan, VP of advanced packaging and nanotechnology at Ultratech, the company’s efforts to scale up its Unity AP300 tool to 450mm will begin with the wafer stage and mechanical scaling during phase one. Phase two will focus on increasing throughput with a new lens design and a different optics configuration, among other changes. “Taking a two-phase approach enables us to minimize risk and meet the time-to-market requirements of our customers,” said Ranjan.
To scale up Ultratech’s laser spike anneal (LSA) technology for 450mm, the first phase of development will include the wafer handling and the stage, explained Jeff Hebb, VP of laser product. This first phase should be done in late 2013, based on the G450 Consortium timeline. Phase two of the effort would be scaling the optics to improve productivity, which could include making the beam 2x longer, or perhaps even using a new laser, or significantly changing the optics. “But there are no technical showstoppers,” stated Hebb. By working on the optics in parallel with the phase one efforts, the company can avoid risking the 2013 date by not including optics redesign or new laser selection in the first phase.
The Experts’ Take on 450mm
Gartner’s analysis indicates that the first production fabs will be ready by 2018 (plus or minus two years) (See Fig. 2). “It’s contingent on lithography being ready,” said Dean Freeman, research VP at Gartner. Laying out a general timeline, Freeman figures that the industry could have pilot line tools shipping in 2013 – with all of them getting into fabs by the end of that year. “Then you’ll probably see beta tools start to emerge in 2014 and 2015.” He added that if the beta tools are good enough to go into pilot line production, there might be pilot lines in the late 2014/2015 timeframe. It might take another two years to wring out the costs and fine-tune the systems, so Freeman projects that the earliest the industry might see production is 2017/2018 – unless efforts are accelerated.
Figure 2. 450mm implementation timelines (dated May 2012). SOURCE: Gartner
Further complications arise if EUV isn’t ready by the time 450mm really comes into play sometime between 10nm and 8nm, noted Freeman. As a result of a delay in EUV, with the attendant costs associated with more patterning steps, there is a possibility that the transition to the next technology node might be slowed. Even at 20nm, Freeman observed that the fabless sector is complaining that the performance/cost ratio is not what has been seen in the past. “Where normally it would be a 28% improvement for a 20-30% better performance, now, we may not see either the performance or cost improvement [for 450mm]. We’re such a cost-sensitive industry that IC manufacturers will look very closely before pulling the trigger on a 450mm fab going forward.”
Adding to the uncertainty is the actual R&D tab for 450mm. “All we have are estimates,” comments Bob Johnson, research VP, at Gartner. “We think the estimate of $15B to $17B for 450mm R&D costs is fairly good.” He also mentioned that SEMI estimates have been as high as $25B to $40B. Noting the importance of obtaining data from alpha tools and subjecting 450mm wafers to “real” processing conditions, Johnson calls the work that the G450 Consortium is doing “absolutely critical.”
Aside from whether or not EUVL will be ready in time for the 450mm transition, there is also a concern about materials development for more advanced (sub-14nm) nodes. “It would probably be too much to bite off and chew to address fundamental materials science challenges and an entire new equipment platform at the same time,” observed Paul Kirsch, director of front-end processes at SEMATECH. “It’s not completely clear how the materials roadmap merges with the 450mm roadmap.” He suggested that it might be more prudent to address fundamental issues with processes, such as CMP and etching, on more mature equipment.
Whatever the worries concerning R&D funding, EUVL delays, or critical materials research, the select group of IC manufacturers and foundries that have the wherewithal are moving forward with 450mm. TSMC’s senior director, 450mm program, C. S. Yoo, explained that the company is engaged with tool suppliers to address the challenges of 450mm manufacturing. “These challenges include tool throughput, cost, and performance,” said Yoo. “We’ve played an active role to support industry efforts to create standards for 450mm production in the Global 450mm Consortium.” Yoo also said that the company plans to set up its own 450mm module line starting in 2014, with volume production after 2016 (Fig. 3).
Figure 3. TSMC’s Fab 12 GIGAFAB located in Hsinchu, Taiwan. The Company’s Phase 7 expansion will incorporate technology for the planned production of 450mm wafers beginning after 2016.
Acknowledgment
GIGAFAB is a trademark of TSMC.