IBM graphene breakthrough leads to chip that's "10,000 times better"
The fragile nature of graphene has previously prevented scientists from exploiting its properties
IBM researchers claim to have built the world’s most advanced graphene chip, with a performance that’s 10,000 times better than previous graphene integrated circuits.
This chip, which is a radio frequency (RF) receiver built on a standard 200mm silicon wafer, is a fairly normal chip complete with resistors, capacitors, and transistors. However, it differs from other chips at the transistor channels, which are made out of graphene. The chip’s job is simply to receive and restore wireless signals in the 4.3GHz range.
In an IBM Research paper published yesterday in Nature Communications, IBM scientists revealed how the graphene receiver successfully extracted the letters "I-B-M" from a 4.3GHz radio broadcast. The digits transmitted were "01001001," "01000010," and "01001101" – a binary encoding of the letters "IBM."
The key to the breakthrough is a new manufacturing technique that allows graphene to be deposited on top of a silicon chip without it being damaged. Up until now, it has been difficult to fabricate graphene into anything useful because of how fragile it is.
The Big Blue researchers discovered a way to add the graphene after its underlying silicon chip is already built instead of constructing the chip around the graphene. The result is an integrated circuit that combines graphene field-effect transistors (GFET) with other components used in radio communications.
The approach is said to work well with traditional silicon CMOS (complementary metal oxide semiconductor) technology for manufacturing chips, making it more likely that the radio-frequency technology can be integrated with other computing functions.
"One can envision that high-performance graphene radio-frequency circuits will be directly built on top of high-density silicon CMOS logic circuits to form an extremely low-cost, ultra-compact communication system," wrote researchers Shu-Jen Han, Alberto Valdes Garcia, Satoshi Oida, Keith A. Jenkins, and Wilfried Haensch.
All photographs: IBM flickr
IBM Graphene Integrated Circuit Fabrication
Three-stage graphene radio-frequency receiver integrated circuit. The top box shows the enlarged SEM image of an IC, revealing the successful integration of key components (inductor, capacitor, and graphene FET). The bottom box shows a single chip which contains dozens of graphene ICs per chip.