by Anton Shilov
07/13/2011 | 10:51 PM
EV Group (EVG), a leading supplier of wafer bonding and lithography equipment has unveiled the semiconductor industry's first bonding system for 450mm-diameter wafers manufactured from silicon-on-insulator (SOI) substrates. The new machines will allow making 450mm SOI wafers that will then used to make chips. The main intrigue is which company will use such wafers first.
The new wafer bonding system - dubbed the EVG850SOI/450 mm - was created to support and facilitate the industry transition to 450mm wafers from the current 300mm standard. The new EVG850SOI/450-mm wafer bonding system is a fully automated tool for production-level fabrication of SOI wafers. Since 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.
Wafer bonding is a crucial technique for fabricating SOI wafers, as it enables achievement of high-quality, single-crystal silicon films on one insulating layer to form SOI substrates
The EVG850SOI/450 mm consists of two process modules: a cleaning module for cleaning and pre-conditioning of wafers before wafer bonding, and an SOI pre-bonding module. In the pre-bonding module, the two silicon wafers are joined together either in a vacuum or in an atmospheric chamber. The tool is equipped with state-of-the-art 450mm load ports and front opening unified pods (FOUPs). Most of the particle and metal ion contamination tests will be performed on 300-mm wafers due to the lack of 450mm metrology systems. The first tool in EVG's 450mm arsenal, the new bonder will serve as the key starting point for the production of 450mm SOI wafers, and can be utilized for the development of other EV Group 450mm products, such as mask aligners and coating systems. An extension of the system with additional modules is planned as a further step to increase wafer throughput.
Leading SOI wafer provider Soitec will install, test and qualify the first EVG850SOI/450mm system at its Grenoble, France, headquarters. Delivery is slated for fall 2011. Unfortunately, it is completely unclear which of the semiconductor manufacturers will actually use such substrates.
At present, the leading semiconductor companies to use silicon-on-insulator wafers are Globalfoundries, IBM and Samsung Semiconductor. Neither Globalfoundries nor IBM have announced plans to migrate to 450mm wafers. Still, there are rumours that Globalfoundries is building new modules of its Fab 8 so that they were 450mm ready. Samsung Electronics has announced collaboration with Intel Corp. and Taiwan Semiconductor Manufacturing Company over standardization of 450mm equipment. But neither Intel nor TSMC plan to use SOI. At this point it is likely that Samsung will be the first to test the 450mm wafers.
"One of the most important SOI fabrication processes based on wafer bonding is the Smart Cut layer transfer technology from Soitec, with whom EV Group has a longstanding collaborative relationship. Soitec is the ideal recipient of the first EVG 450mm SOI wafer bonding system, and their evaluation of the alpha-tool will be invaluable for optimizing the system modules,” said Paul Lindner, executive technology director of EV Group.
According to EVG, SOI is expected to play an enabling role in the shift to 450 mm, as it not only answers most of the scaling challenges, but it also delivers better power/performance for sub-22nm CMOS and 3D technologies compared to similar-geometry bulk CMOS.
"Soitec is willing to position in the 450-mm transition. 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,” said Paul Boudre, chief operating officer of Soitec.