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November 15, 2007

Silicon electronics can be printed by Ink Jet printers

Kovio, sunnyvale startup, jas the world's first all-printed silicon transistor capability. They will have roll to roll printing of computers. This is clearly a process that will get even better as the design rules shrink and as they use faster printing technology like Memjet This technology also has implications for better fabbers, rapid prototyping and rapid manufacturing over the next few years.

This could foreshadow some prior to nanofactories style breakthroughs. New near-nanotech could make breakthroughs that can drive cost and applications that cannot be matched by silicon CMOS tech. Ovonic quantum control devices on polymer might have a performance advantage instead of disadvantage versus silicon chips. New nanopatterning systems could get the component sizes down as well.

Super-electronics based on polymer or graphene might be made from far cheaper fabs and far greater flexibility in form factors and cost reductions and even higher volumes.

Better versions or alternatives to this technology might also transform solar photovoltaics.

Its "green" silicon ink for thin-film transistors (TFTs) that achieve the performance of polysilicon transistors, but at a third their price and consuming only 5 percent of the chemicals and 25 percent of the energy of single-crystal silicon. Kovio claimed that radio-frequency identification tags using its silicon ink will drop Kovio's price from 15 cents today to 5 cents by 2008, when Kovio begins volume production of its inkjet-printed RFID tags.

Their thin-film silicon transistors have very high mobilities for a printed device and we can make both p-type and n-type devices for CMOS circuits. Right now their design rules are 20 micron, but they have 10 micron working in the lab, which is where Intel started in 1971. Intel's first microprocessor used just over two thousand transistors: similarly, their first devices for RFID tags will use less than about a thousand transistors when we go into mass production by the end of next year [2008]

Kovio is building its own fab, which uses temperatures too high for plastic substrates (which is why Kovio uses a stainless steel foil substrate), but which does not require the expensive processing equipment and clean-room environment of single-crystal silicon fabs. Silicon ink devices can be fabricated on roll-to-roll printing equipment, which is how Kovio plans to dramatically drop the price of RFID tags and similar applications using all types of flexible electronics.

They can build a printable silicon fab for about $10 million, compared with $1 billion for a traditional silicon fab. They need only about five percent of the materials (one percent of substrate cost and three percent of the cycle time) to create new devices.

By way of comparison, single crystal silicon transistors today can achieve mobilities as high as 600 centimeters squared per volt second (sq cm/Vs), and polysilicon transistors, like those that drive LCD displays, have mobilities of about 100 sq cm/Vs. Unfortunately, there is a big gap between single-crystal silicon and the printable organic transistors that are being demonstrated at dozens of labs worldwide. Organic transistors have dismal electron mobilities of less than 1 sq cm/Vs in contrast with Kovio's silicon ink, which rivals polysilicon with its 80 sq cm/Vs electron mobilities. Most important, silicon ink can produce transistors that are fast enough for RFID and most other electronic interface protocols.

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