In June 2006, the first silicon-germanium (SiGe) transistor able to operate at frequencies above 500 GHz was demonstrated by a research team from IBM and the Georgia Institute of Technology (Georgia Tech). This high speed world record was achieved at a an extremely cold 4.5 degrees Kelvin (-451 degrees Fahrenheit) attained by liquid helium cooling. photograph shows a SiGe chip inside a cryogenic test station observed by a Georgia Tech researcher. At approximately 350 GHz, the performance of the transistor at room temperature was also impressive. Much higher (near-terahertz [THz]) operational frequencies at room temperature are believed to be attainable with future SiGe technology.
Chips made of the SiGe alloy have increased performance and reduced power consumption over chips made of pure Si. Potential applications of ultra-high-frequency SiGe circuits with extreme levels of transistor performance include cell phones and many more advanced communications systems, defense systems, space electronics platforms, and remote sensing systems. Ultra-high-frequency SiGe technology is desirable because of the low cost of standard high-volume silicon-based manufacturing processes.
More information on 500 GHz transistor from the Georgia Tech webpage.
