LONDON – Infineon Technologies AG has claimed it is the first and only company worldwide to produce power semiconductors on 300-millimeter thin wafers and that this will bring the company both a technical and cost advantage over its competition.
Infineon (Munich, Germany) has been working on the technology for several years and in February 2013 received first customer clearances to ship CoolMOS family products made on a 300-mm production line at Villach, Austria, which uses thin wafers. The chips are now being shipped worldwide, Infineon said.
As power flows vertically in a power MOSFET the reduced thickness lowers resistance and losses and allows heat to be removed more effectively. Infineon has worked with thinned wafers or thin epitaxial structures on top of wafers for more than a decade. However, transferring such a process to 300-mm wafers sets additional challenges.
Infineon did not indicate what power ICs are the first to ship from 300-mm wafers but is reported to have been working on power MOSFETs and insulated-gate bipolar transistors (IGBTs). A wafer is typically 350-microns thick prior to being diced into individual chips. At the 200-mm wafer size Infineon typically thins power wafers back to 60-micron and even 40-micron thicknesses. The technology is used for IGBTs) and high- and low-power MOSFETs for a range of applications from automotive engine control through to power packs and induction hobs.
The larger size of 300-mm wafer compared to 200-mm wafers used as standard for power IC production means two-and-a-half times as many chips can be made from each one providing a cost advantage to Infineon.
"Infineon put its faith in this manufacturing technology very early on and continued to invest even in economically difficult times," said Reinhard Ploss, CEO of Infineon, in a statement. "The qualification of our entire 300-millimeter line represents a veritable leap ahead of the competition," he added.
Infineon plans to add the approval of its back-end packaging site in Malacca, Malaysia and then to expand production to its front-end site in Dresden, Germany, where a fully automated 300-mm production line will focus on high volume production.
The technology transfer to Dresden is running on schedule and qualification of the first CoolMOS products will be completed in March 2013, Infineon said. Meanwhile Villach will work on transferring more power semiconductor technologies to 300-mm production.
Infineon produces power MOSFETS on thin, 300-mm diameter wafers
Do they actually process the wafers thru the fab when they are thin? That would lead to many issues for conformity across the wafer during critical process steps. I think what they are saying, is that they thin the wafer (back grind) after processing. They are just making the wafer thinner than most semiconductor suppliers. I guess this gives them better heat conduction. I don't see how this gives them a cost advantage.
Do wafers actually become "floppy" when thinned to this degree? I see the image but it still seems that the lattice structure would prevent that degree of deflection. Manufacturing on floppy wafers would actually be very good because it could significantly ease wafer handling requirements.