New material structure produces world's fastest transistor

Maybe y'all knew this already, or maybe it's not immediately useful to
anyone. Rather sparse article too, but possibly interesting. If
posting things like this in sci.electronics.basics is a no-no or
otherwise frowned upon, kindly let me know :+:

Source: http://www.physorg.com/news3662.html

The new device -- built from indium phosphide and indium gallium
arsenide -- is designed with a compositionally graded collector, base
and emitter to reduce transit time and improve current density. With
their pseudomorphic heterojunction bipolar transistor, the researchers
have demonstrated a speed of 604 gigahertz -- the fastest transistor
operation to date.

"Pseudomorphic grading of the material structure allows us to lower the
bandgap in selected areas," said Milton Feng, the Holonyak Professor of
Electrical and Computer Engineering and a researcher at the Coordinated
Science Laboratory at Illinois. "This permits faster electron flow in
the collector. The compositional grading of the transistor components
also improves current density and signal charging time."

Feng and graduate student Walid Hafez fabricated the new device in the
university's Micro and Nanotechnology Laboratory. They describe the
pseudomorphic HBT concept, and discuss the transistor's high-speed
operation, in the April 11 issue of the journal Applied Physics
Letters.

The goal of a terahertz transistor was not possible using the previous
device structure, Feng said. "To achieve such speed in a typical HBT,
the current density would become so large it would melt the components.
In our pseudomorphic HBT, we can operate at higher frequencies with
less current density. With this new material structure, a terahertz
transistor is achievable."

Faster transistors could facilitate faster computers, more flexible and
secure wireless communications systems, and more effective electronic
combat systems.

 

go on, I like the electronic combat systems.