The transistor, made in Germany using a 130-nm BiCMOS process, achieved a fmax of 798GHz at a temperature of 4.3K and with a breakdown voltage of 1.7V. The frequency exceeding the previous speed record for silicon-germanium chips by about 200 GHz. At room temperature the same transistor was operated at 417 GHz.
The research was published in IEEE Electron Device Letters and although the record was broken at extremely cold temperatures Professor John Cressler, who led the research for Georgia Tech. reckons record speeds could also be reached at room temperature.
"The transistor we tested was a conservative design, and the results indicate that there is significant potential to achieve similar speeds at room temperature - which would enable potentially world-changing progress in high-data-rate wireless and wired communications, as well as signal-processing, imaging, sensing and radar applications," said Cressler, in a statement issued by IHP. "Moreover, I believe that these results also indicate that the goal of breaking the so-called 'terahertz barrier' - meaning, achieving terahertz speeds in a robust and manufacturable silicon-germanium transistor – is within reach."
The 800GHz transistor was manufactured using IHP's 130nm BiCMOS process, which is offered by IHP in a multi-project wafer foundry service.