Intel and Qinetiq build 150 GHz InSb transistor
A collaborative project between Intel and UK-based research company Qinetiq has developed InSb transistors with a cut-off frequency of 150 GHz.
According to the research team, the quantum-well devices, which have a gate length of 200 nm, have a power dissipation 5-10 times lower than state-of-the-art silicon MOSFETs.
The low power consumption is thanks to the much higher mobility of the novel material compared with silicon and GaAs at room temperature, which means that the operating voltage of the transistors is just 0.5 V.
"This makes the InSb technology a viable option for ultrahigh-speed, very low power digital and RF applications," said the team in a paper presented at the International Conference on Solid-State and IC Technology in Beijing.
While similar technology has been previously demonstrated on an InSb substrate, these latest transistors are fabricated on a semi-insulating GaAs wafer.
First, a relaxed metamorphic buffer layer of AlInSb is deposited on top of the substrate. This is followed by a compressively-strained InSb quantum well sandwiched between two more AlInSb layers with a different Al/In composition to the buffer layer.
The InSb quantum well transistors can operate at three times the speed of state-of-the-art silicon while consuming the same power, or can switch at the same speed while consuming up to ten times less power.
Unlike most transistors, which rely on the application of a voltage to be switched "on", the InSb NMOS devices are "always on". Instead, they are switched off by applying a negative voltage to the gate.
Intel says that the technology, which was initially developed under a UK Ministry of Defence project, is only one of many new materials that it is investigating for future chip generations.