Comparative Evaluation of Ferroelectric Negative Capacitance MFMIS and MFIS Transistors for Analog/Radio-Frequency Applications

As the negative capacitance field-effect transistors (NCFETs) have extensive application prospects and advanced technological support in the analog/radio-frequency (RF) domains, it is important to investigate the theoretical performances of the NCFETs with various feasible structures. In this article, utilizing the TCAD simulation tool and an experimentally calibrated ferroelectric model, we perform a comparative evaluation of MFMIS and MFIS, two prominent NCFET configurations, with regard to their DC/static characteristics and analog/RF performances. Through simulations involving varying ferroelectric thicknesses, it is seen that in comparison with the MFIS device, the MFMIS device demonstrates superior static performances in on-state current (
I
_ON
), off-state current (
I
_OFF
) and subthreshold swing (
SS
), and the underlying physical effects of these results have also been uncovered. Furthermore, we extracted the device-level analog/RF figures of merits (FoMs) like transconductance (
g
_m
), gate capacitance (
C
_gg
), output conductance (
g
_d
), cutoff frequency (
f
_T
), transconductance generation factor (
TGF
), transconductance frequency product (
TFP
), etc from the two structures. It is found that the MFMIS device still possesses advantages in these parameters, and as the thickness of ferroelectric layer increases, the advantages compared to the MFIS device become more pronounced. The investigations in this article indicate that the MFMIS NCFET exhibits superior adaptability and performances in enhancing the analog/RF capabilities of conventional devices as compared with the MFIS device.