Theoretical and experimental determination of onset and scaling of non-quasi-static phenomena for interdigitated fin field effect transistors

The efficient development of device fabrication and circuit design for microwave applications require a thorough analysis of the microwave performance of the intrinsic transistor with respect to the total gate periphery, since enlarging the transistor channel width allows in obtaining higher levels of output current and gain. Oftentimes, this analysis is carried out by using the intrinsic equivalent circuit elements and their conventional scaling rules. In contrast to that, the purpose of this study is to investigate the scaling of the microwave transistor behaviour directly by using the intrinsic admittance parameters in the microwave frequency range up to 50 GHz. In particular, the scalability and the onset frequency of the non-quasi-static effects for interdigitated fin field effect transistors is theoretically and experimentally analysed against the number of fingers. The results reveal that the onset frequency of the non-quasi-static phenomena is mainly determined by the time constant of the output RC network, which is due to the lossy substrate, and its value is roughly independent of the gate width.