The world’s fastest transistor has been developed by a pair of US researchers, possibly paving the way for a new generation of super-charged electronic chips.
Milton Feng and Walid Hafez at the University of Illinois at Urbana-Champaign, developed the record-breaking transistor by carefully blending different semiconducting materials within individual layers of the microscopic device.
Transistors are basic components within electronic circuits. They are used as tiny electronic switches or current amplifiers or for a variety of other tasks. Modern computer chips - like Intel’s Pentium 4 - contain millions of individual transistors and the fundamental efficiency of these chips depends on the speed at which their transistors operate.
Feng and Hafez developed a transistor less than half a millionth of a metre long, with a maximum operating speed of 604 GHz, meaning it can carry out 604 billion operations every second.
“This establishes a new benchmark for transistor performance,” says Doug Barlage at North Carolina State University, US. “It is probably three times faster than the fastest silicon-based device.
Sandwiched layers
Feng and Hafez developed a particular type of component known as a bipolar junction transistor, which consists of three material layers, laid on top of one another.
The current is controlled by the way it passes through three layers - the base, emitter and collector layers. Varying the current which passes through the base to the emitter can control the flow of the current between the emitter and collector. This can amplify the current at that terminal or be used to switch the current on or off.
To make their transistor layers, the researchers carefully blended together two different crystalline semiconducting materials: indium phosphide and indium gallium arsenide. Critically, they controlled the blend found in the “collector” layer to affect its crystalline structure in a way which made it easier for electrons to pass through - this was a crucial step in making the transistor so efficient.
Farther and faster
“By grading the collector material to higher indium content, the mobility of the material increases, meaning the electrons can travel faster through the collector region,” Hafez told New Scientist.
The carefully created mixture has another key benefit. “The electrons can travel not only faster, but they can travel longer distances at incredibly high speeds before they are finally slowed down by running into atoms in the collector,” Hafez adds.
But Hafez admits it will be a while before the component can be used in a complex electronic device. “We’re still a long way from building a chip using the transistor,” he told New Scientist. “But once we develop a circuit we can start working on more complex ones.”
Barlage adds that the material may be less well suited for use in other forms of transistor, such as those that are controlled by an electric field - field-effect transistors are commonly used in computers. But, he suggests, “it is not out of the question”.
Kevin Krewell, editor-in-chief of Microprocessor Report, an industry publication, believes the material would be ideally suited to use in radio receivers. “The higher the transistor frequency, the more processing can be done on the signals,” he says.
By NewScientist
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