Comparative analysis of full-gate and short-gate dielectric modulated electrically doped Tunnel-FET based biosensors. (November 2017) - Sharma, Dheeraj
Abstract: In this work, we have done a comprehensive study between full-gate and short-gate dielectrically modulated (DM) electrically doped tunnel field-effect transistor (SGDM-EDTFET) based biosensors of equivalent dimensions. However, in both the structures, dielectric constant and charge density are considered as a sensing parameter for sensing the charged and non-charged biomolecules in the given solution. In SGDM-EDTFET architecture, the reduction in gate length results a significant improvement in the tunneling current due to occurrence of strong coupling between gate and channel region which ensures higher drain current sensitivity for detection of the biomolecules. Moreover, the sensitivity of dual metal SGDM-EDTFET is compared with the single metal SGDM-EDTFET to analyze the better sensing capability of both the devices for the biosensor application. Further, the effect of sensing parameter i.e., ON-current (I ON ), and I ON /I OFF ratio is analysed for dual metal SGDM-EDTFET in comparison with dual metal SGDM-EDFET. From the comparison, it is found that dual metal SGDM-EDTFET based biosensor attains relatively better sensitivity and can be utilized as a suitable candidate for biosensing applications. Highlights: In this work, we perform comparative analysis between full-gate and short-gate DM-EDTFET based biosensors. However, dual metal concept is introduced in SG-DM-EDTFET which offers significant improvement in the sensitivity over single metal device. It is important to point out that biasing condition decides a precise biasing range for achieving maximum sensitivity enhancement of dual metal device over other architecture. Besides structurally enhanced conjugation effect on gate-channel coupling, the presented work has also shown that gate material engineering is also a main reason for the sensitivity enhancement. For future, the proposed device can be utilized as highly sensitive device for making an ultra-sensitive label-free biomedical equipment.