450mm Wafer Manufacturing Tools Ready
The long-debated transition to semiconductor processing using 450mm diameter silicon wafers — the next size after 300mm — has reached a major milestone with new tools released for the production of bulk silicon and silicon-on-insulator (SOI) wafers. Before original equipment manufacturers (OEM) can begin developing IC fabrication tools, the wafer manufacturers need the capabilities to produce the substrates needed for process development and integration. During SEMICON West 2011, KLA-Tencor announced the availability of a 450mm unpatterned wafer inspection system, and EV Group unveiled the first bonding system for 450mm SOI substrates.
KLA-Tencor’s next generation of wafer defect and surface quality inspection systems, the Surfscan SP3, is designed for extension to 450mm (figure). As the first unpatterned wafer inspection platform to incorporate deep-ultraviolet (DUV) illumination, the tool feature dramatic advances in sensitivity and throughput over the prior SP2XP model. The SP3 also offers a module that inspects the back side of wafers for defects that might deform the wafer shape during photolithography.
The Surfscan SP3 system is designed to help develop and manufacture substrates for <28nm devices that are nearly atomically smooth and free from polish marks, crystalline pits, terracing, voids or other defects that disrupt the electrical integrity of the transistor. Because these defects cannot be reliably detected by current-generation inspection systems at production speeds, substrate manufacturers have had difficulty achieving satisfactory yields with these top-grade, next-node wafers. KLA-Tencor’s engineers have built the Surfscan SP3 inspection system with the DUV sensitivity and throughput needed to reliably identify critical defects and surface quality issues inline during substrate manufacturing.
EV Group unveiled the semiconductor industry’s first bonding system for 450mm wafers manufactured from SOI substrates this week. Building on EVG’s strength in SOI wafer bonding, the new system — dubbed the EVG850SOI/450 mm — was created to support and facilitate the industry transition to 450mm wafers from the current 300mm standard. Leading SOI wafer provider Soitec will install, test and qualify the first of this new system at its Grenoble, France, headquarters, starting in the fall of this year.
Noted chief operating officer Paul Boudre of Soitec, “With the launch of this new system, EV Group is offering the semiconductor industry a highly viable solution to ease the transition to 450mm wafers. With our well established SOI material playing an increasingly greater role in fabricating next-generation ICs, we look forward to working with EVG to ensure this new system is ready to enter mainstream production in a timely fashion.
Because chipmakers will need an interim solution to optimize productivity for existing 300mm capacity as the migration to 450mm proceeds over the next few years, the system can serve as a bridge tool, allowing processing of both wafer sizes.
“Every bonded 300mm SOI wafer and nearly 100 percent of all SOI wafers are fabricated on EVG systems. We delivered our first SOI bonding system in 1994, and our global installed base continues to grow with widened adoption of SOI substrates,” noted EV Group executive technology director Paul Lindner.
BrightSpots 450mm online forum
Lindner was one of the panelists who launched an online 450mm web forum in a live panel discussion July 11 in San Francisco. Other panelists at the “BrightSpots” live event, sponsored by public relations firm MCA, were Michel Brillouet, executive with CEA-Leti; Risto Puhakka, president of VLSI Research; and Gus Richard, analyst with Piper Jaffray.
Much of the concern regarding the transition to 450mm wafers is due to the OEMs’ painful experiences in transitioning from 200mm wafer to 300mm wafers. There was excessive promotion of the global need for 300mm wafers ahead of the real demand so that OEMs invested resources into bringing tools to market only to be told that the market wasn’t ready yet. In some cases, the tool was designed for the specifications of a particular technology node and then had to be redesigned to meet the specifications of the next node when the real demand started.
Puhakka reminded everyone of one of the key lessons from the last wafer size transition: the economics completely change before and after the transition. Before the transition, 200mm wafer tools were the proven conservative approach to production. After the transition to 300mm, 200mm lines could not compete on a cost basis and some companies were stuck with uncompetitive billion-dollar investments. So, presuming that an IC manufacturer anticipates running sufficient volumes of chips to be able to justify the capacity of a 450mm fab, it should be far less expensive than running two 300mm fabs. “No company wants to be the last to build a 300mm fab,” reminded Puhakka.
Who can afford a 450mm fab? Richard quipped that it’s “ITS: Intel, TSMC. And Samsung. The issue is the factory is going to cost $9 to $12 billion dollars, so the revenue run-rate will have to be $15 to $20 billion.
When will the first 450mm IC fab come on line? “Volume manufacturing at 450mm is probably about five years away, but development has to start now,” said Lindner. “I think that every major tool maker has a 450mm program even though they might not talk about it in public. So the tool development is underway, but the hurdle today is the process development and integration.”
“Even for 14nm it is probably too late, so the first possible insertion node will probably be 10nm or below,” said Brillouet. Puhakka responded that he’s not sure about the specific node, but VLSI Research has been saying for many years that the time frame for 450mm will be 2020 to 2025.
The BrightSpots 450mm discussion continues asynchronously online through the end of next week. Join in the conversion, and post questions to these experts at www.infoneedle.com/MCA450 until July 22.
– Ed Korczynski