The investigators operated a silicon-germanium (SiGe) transistor at 798 gigahertz (GHz) fMAX, exceeding the previous speed record for silicon-germanium chips by about 200 GHz.
Although these operating speeds were achieved at extremely cold temperatures, the research suggests that record speeds at room temperature aren't far off, said professor John D. Cressler, who led the research for Georgia Tech. Information about the research was published in February of 2014, by IEEE Electron Device Letters.
"The transistor we tested was a conservative design, and the results indicate that there is significant potential to achieve similar speeds at room temperature – which would enable potentially world-changing progress in high-data-rate wireless and wired communications, as well as signal-processing, imaging, sensing and radar applications," said Cressler, who hold the Schlumberger Chair in electronics in the Georgia Tech School of Electrical and Computer Engineering. "Moreover, I believe that these results also indicate that the goal of breaking the so-called ‘terahertz barrier’ – meaning, achieving terahertz speeds in a robust and manufacturable silicon-germanium transistor -- is within reach."
Meanwhile, Cressler added, the tested transistor itself could be practical as is for certain cold-temperature applications. In particular, it could be used in its present form for demanding electronics applications in outer space, where temperatures can be extremely low.
IHP, a research center funded by the German government, designed and fabricated the device, a heterojunction bipolar transistor (HBT) made from a nanoscale SiGe alloy embedded within a silicon transistor. Cressler and his Georgia Tech team, including graduate students Partha S. Chakraborty, Adilson Cordoso and Brian R. Wier, performed the exacting work of analyzing, testing and evaluating the novel transistor.
“The record low temperature results show the potential for further increasing the transistor speed toward THz at room temperature. This could help enable applications of Si-based technologies in areas in which compound semiconductor technologies are dominant today. At IHP, B. Heinemann, H. Rücker, and A. Fox supported by the whole technology team working to develop the next THz transistor generation,” according to Bernd Tillack, who is leading the technology department at IHP in Frankfurt (Oder), Germany.
Silicon, a material used in the manufacture of most modern microchips, is not competitive with other materials when it comes to the extremely high performance levels needed for certain types of emerging wireless and wired communications, signal processing, radar and other applications. Certain highly specialized and costly materials – such as indium phosphide, gallium arsenide and gallium nitride – presently dominate these highly demanding application areas.But silicon-germanium changes this situation. In SiGe technology, small amounts of germanium are introduced into silicon wafers at the atomic scale during the standard manufacturing process, boosting performance substantially.
The result is cutting-edge silicon-germanium devices such as the IHP Microelectronics 800 GHz transistor. Such designs combine SiGe's extremely high performance with silicon's traditional advantages -- low cost, high yield, smaller size and high levels of integration and manufacturability -- making silicon with added germanium highly competitive with the other materials.Cressler and his team demonstrated the 800 GHz transistor speed at 4.3 Kelvins (452 degrees below zero, Fahrenheit). This transistor has a breakdown voltage of 1.7 V, a value which is adequate for most intended applications.
The 800 GHz transistor was manufactured using IHP’s 130-nanometer BiCMOS process, which has a cost advantage compared with today’s highly-scaled CMOS technologies. This 130 nm SiGe BiCMOS process is offered by IHP in a multi-project wafer foundry service.
The Georgia Tech team used liquid helium to achieve the extremely low cryogenic temperatures of 4.3 Kelvins in achieving the observed 798 GHz speeds. "When we tested the IHP 800 GHz transistor at room temperature during our evaluation, it operated at 417 GHz," Cressler said. "At that speed, it's already faster than 98 percent of all the transistors available right now."Contacts:
Dr. Wolfgang Kissinger | idw
Superfast fluorescence sets new speed record
27.07.2015 | Duke University
Two crystals are better than one
22.07.2015 | The Agency for Science, Technology and Research (A*STAR)
Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.
Joint BioEnergy Institute study identifies bacterial protein that is key to protecting rice against bacterial blight
A bacterial signal that when recognized by rice plants enables the plants to resist a devastating blight disease has been identified by a multi-national team...
Researchers in the Cockrell School of Engineering at The University of Texas at Austin are one step closer to delivering smart windows with a new level of energy efficiency, engineering materials that allow windows to reveal light without transferring heat and, conversely, to block light while allowing heat transmission, as described in two new research papers.
By allowing indoor occupants to more precisely control the energy and sunlight passing through a window, the new materials could significantly reduce costs for...
Argonne scientists used Mira to identify and improve a new mechanism for eliminating friction, which fed into the development of a hybrid material that exhibited superlubricity at the macroscale for the first time. Argonne Leadership Computing Facility (ALCF) researchers helped enable the groundbreaking simulations by overcoming a performance bottleneck that doubled the speed of the team's code.
While reviewing the simulation results of a promising new lubricant material, Argonne researcher Sanket Deshmukh stumbled upon a phenomenon that had never been...
A NASA camera on the Deep Space Climate Observatory (DSCOVR) satellite has returned its first view of the entire sunlit side of Earth from one million miles away.
The color images of Earth from NASA's Earth Polychromatic Imaging Camera (EPIC) are generated by combining three separate images to create a...
23.07.2015 | Event News
10.07.2015 | Event News
25.06.2015 | Event News
29.07.2015 | Earth Sciences
29.07.2015 | Life Sciences
29.07.2015 | Life Sciences