Case Studies - Information, Communication and Electronics

QinetiQ has developed high speed, low power consumption transistors based on indium antimonide technology. This proprietary technology allows a significant leap in circuit performance.

The need for ever higher circuit speeds, for both faster logic and higher communications bandwidth, is recognised throughout the world. In addition, the need for lower power consumption is becoming ever more pressing, especially in portable equipment.

To meet this need, QinetiQ has developed Indium Antimonide transistor technology - potentially the fastest and lowest power technology in the world. Indium Antimonide (InSb) has the highest electron mobility, electron velocity and ballistic length of any semiconductor material, making it potentially the ideal material for making high-speed, low-power, low-noise transistors and circuits.

QinetiQ has pioneered the use of carrier exclusion/extraction techniques to remove the large number of intrinsic carriers present in this material, which would otherwise cause excess leakage and give poor operation.

Our proprietary 'extracted' transistors recover normal transistor operation, allowing the fundamental advantages of the material to shine through. The technology offers high-gain, low power consumption active devices which can be used to give greatly enhanced performance in a variety of microwave and mm-wave circuits, such as low-noise and other amplifiers, and small digital processors, giving very attractive options for communications and ultra high speed digital signal processing. An InSb circuit will process more information per second than any other technology, and more information per battery as well in a portable device, making it doubly advantageous.

We have shown that transistors made from InSb show the highest switching speeds of any devices of their size, with a 0.7 µm field effect device switching at over 85 GHz. Device modelling suggests that THz performance is possible with smaller devices. Another highly desirable feature of the devices is that they operate at below 0.5 V, greatly reducing the power consumed by a circuit based on InSb technology. The extraction technology also works for bipolar devices, and we have demonstrated excellent performance in a test device. We are currently looking to work with industrial partners to develop this technology into a commercial process.