Impact of Mole Fraction Variation on the pH Sensing Performance of SiGe channel based Polarity Controllable Ion Sensitive FET – Part-II

In the present study, the efficacy of proposed Silicon-Germanium channel-based polarity controllable-ion sensitive FET (SiGe–PC–FET) is investigated in terms of output drain characteristics, and sensitivity in terms of ratio of ON– state current to OFF– state current and transconductance. Further, the effect of mole fraction on these characteristics has also been accounted. It has been found that for n-mode operation, lower mole fraction (m = 0.1) and for p-mode, higher mole fraction offers superior pH sensing response. Furthermore, at 0.8 V of reference electrode potential, the average value of transconductance sensitivity demonstrated by n- (p-) mode of proposed SiGe–PC–FET is 3.75 x 10
⁻⁷
(3.24 x 10
⁻⁶
) S/( μm x pH) for mole fraction value m = 0.1 (0.3) respectively.