20.2 GHz-mu m f(T)-L-G in InAlN/GaN-on-Si High Electron Mobility Transistors

Herein, InAlN/GaN-on-Si high-electron-mobility transistors (HEMTs) with an f(T)-L-G product of 20.2 GHz-mu m are demonstrated. The device with a gate length of 200 nm and a source-drain spacing of 900 nm exhibits a peak transconductance of 543 mS mm(-1), an I-ON/I-OFF ratio of approximate to 10(7), a maximum on-current of 2.4 A mm(-1), and an on-resistance of 1.07 omega mm. Small-signal characteristics show a unity current gain cutoff frequency of 101 GHz. Delay time analysis is performed to evaluate various delay components and their contribution to the small-signal performance of the device. An effective electron velocity of 1.56 x 10(7) cm s(-1) is estimated in these devices, which minimizes the intrinsic delay of the transistor. The factors limiting the f(T)-L-G product in deeply scaled devices are discussed using the delay analysis.