The invention relates to the technical field of
semiconductor devices, in particular to a
biosensor of a
tunneling field effect transistor based on a barrier gate structure, which comprises a
silicon substrate, an insulating layer, a channel, a
gate dielectric layer, a source
electrode, a drain
electrode, a gate
electrode, a biological nano cavity and a biological
dielectric layer, the
silicon substrate, the insulating layer, the channel and the
gate dielectric layer are sequentially stacked from bottom to top; the source electrode and the drain electrode are distributed on two sides of the channel, are in contact with the channel and the
gate dielectric layer, and are laminated on the upper surface of the insulating layer; the end part, close to the source electrode, of the channel is a P + doped region, and the end part, close to the drain electrode, of the channel is
graphene; the end part, close to the P + doped region, of the
graphene is an N + doped region, and the middle part of the
graphene is a P barrier region; the biological nanometer cavity and the grid electrode are sequentially stacked on the upper surface, right facing the P barrier region, of the grid
dielectric layer. The biological medium layer is stacked on the side face, close to the source electrode, of the biological nanometer cavity and makes contact with the grid electrode. Off-state current is reduced,
power consumption is reduced, the switching current ratio is increased, and the problem that a
biosensor in the prior art is low in sensitivity is solved.