US researchers have cast doubt on the elastic tunnelling model
for transistor noise.
"The model was a good working theory when transistors were
large, but our observations clearly indicate that it's incorrect at
the smaller nanoscale regimes where industry is headed," said
scientist Jason Campbell of the US
National Institute of
Standards and Technology (NIST)
The theory predicts that as transistors shrink, noise
fluctuations should correspondingly increase in frequency.
However, Campbell's group claims that even in nanometre-sized
transistors, the fluctuation frequency remains the same. "This
implies that the theory explaining the effect must be wrong," said
Campbell.
According to Campbell, the noise he is working on also increases
as power reduces in the device.
"This is a real bottleneck in our development of transistors for
low-power applications," he said. "We have to understand the
problem before we can fix it - and troublingly, we don't know
what's actually happening."