High-electron mobility transistors (HEMTs) have become an important device for high frequency and low noise applications. The performance of these devices has been pushed into the range of several hundred GHz for fT. One question that has been asked is just how high a frequency can be obtained with these devices. To study this question, we have used a full-band, cellular Monte Carlo transport program, coupled to a full Poisson solver to study a variety of InAs-rich, InGaAs pseudomorphic HEMTs and their response at high frequency. We have concentrated on pseudomorphic HEMTs with the structure (from the substrate) InP/InAlAs/InGaAs/InAlAs/InGaAs, with the quantum well composed of In 0.75Ga0.25As, and have studied gate lengths over the range 10-70 nm. Various source-drain spacings have also been studied, and the performance of scaled devices evaluated to determine the ultimate frequency limit. Here, the importance of the effective gate length has been evaluated from the properties internal to the device.
ASJC Scopus subject areas
- Physics and Astronomy(all)