Chip boffins demo 22-nanometer maskless wafer-baking
A possible savior when Moore's Law hits the light wall
An international consortium of chip boffins has demonstrated a maskless wafer-baking technology that they say "meets the industry requirement" for next-generation 14- and 10-nanometer process nodes.
Current chip-manufacturing lithography uses masks to guide light onto chip wafers in order to etch a chip's features. However, as process sizes dip down to 20nm and below, doubling up on masks begins to become necessary – an expensive proposition.
At last November's 40th birthday party for the pioneering Intel 4004 microprocesser, The Reg asked Intel Labs' director of microprocessor technology research Shekhar Borkar if multiple masks might be the solution to ever-tinier process nodes. He told us, that, yes, it would be possible, but that adding masks increases both complexity and cost.
One solution would be to eliminate lithography masks altogether, and etch the chips directly with guided electron beams – think old-style cathode-ray tubes, but with much smaller, much more tightly controlled beams.
That's exactly what MAPPER Lithography of Delft, The Netherlands, has done in conjunction with CEA-Leti, the French Research and Technology Institute, in a project dubbed IMAGINE, an effort joined by such industry heavyweights as TSMC and STMicroelectronics, as well as Nissan Chemical, TOK, Dow Chemical, JSR Micro, Synopsys, Mentor Graphics, Sokudo, Tokyo Electron, and Aselta Nanographics.
MAPPER's breakthrough has been to demonstrate a chip-etching technology that uses 10,000 precisely directed electron beams that etch features directly onto a wafer. As explained in their announcement, "The major achievement has been obtained in resolution: 22nm dense lines and spaces and 22nm dense contact holes in positive chemically amplified resist have been successfully resolved."
Don't expect this technology to supplant mask-based photolithography any time soon, however. This year, MAPPER plans to introduce a "pre-production" version of its Matrix system that will have a slo-mo throughput of one wafer per hour, and which the company plans to scale up to 10 wafers per hour.
"Given the great results we have obtained at CEA-Leti thus far," MAPPER CEO Bert Jan Kampherbeek said in his company's announcement, "we are proud to announce that one of the first Matrix systems will be installed at CEA-Leti to enable the continuation of the IMAGINE programme."
The Matrix system will indeed be slow – but so are current versions of one of traditional chip lithography's waiting-in-the-wings saviors, extreme ultraviolet (EUV) lithography "To have a fab running economically, you need to build about two to three hundred wafers an hour," the head of ARM's Physical IP Division Simon Segars said at last year's Hot Chips conference. "EUV machines today can do about five."
The jury remains out on what will take over from conventional lithography when it hits the multi-mask wall – but seeing as how even EUV will require expensive masks, the maskless Matrix system and its follow-ons just became a viable contender. ®
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