Approach for the improvement of sensitivity and sensing speed of TFET-based biosensor by using plasma formation concept

摘要

In this work, a new design of dual-gate source electrode (SE) dielectric-modulated tunnel field-effect transistor (TFET) biosensor with improved sensitivity and sensing speed has been presented. For this, P + (source) I (channel) N + (drain) type conventional TFETs structure is initially considered for comparison. Further to this, for the first time, an additional electrode is placed over the physically doped source region of the conventional biosensor with the negative supply voltage for extension of the cavity over the source region. The use of extra SE with negative supply voltage for the formation of cavity over the source region overcome the issues related to the formation of abrupt junction (at source/channel junction) and solubility limit of silicon material by the formation of a plasma layer of holes near to Si/HfO₂interface in the source region. Moreover, the presence of extra biomolecules in the source cavity region of the proposed device further increases the concentration of plasma layer of holes near to Si/HfO₂due to better coupling of SE and source region which is responsible for the improvement in sensing capability and sensing the speed of TFET biosensor. In this concern, a comparative investigation has been performed.