  Silicon bipolar impact ionization MOSFET offers the potential for realization
of leaky integrated fire (LIF) neuron due to the presence of parasitic BJT in
the floating body. In this work, we have proposed an L shaped gate bipolar
impact ionization MOS (L-BIMOS), with reduced breakdown voltage ($V_{B}$ = 1.68
V) and demonstrated the functioning of LIF neuron based on positive feedback
mechanism of parasitic BJT. Using 2-D TCAD simulations, we manifest that the
proposed L-BIMOS exhibits a low threshold voltage (0.2 V) for firing a spike,
and the minimum energy required to fire a single spike for L-BIMOS is
calculated to be 0.18 pJ, which makes proposed device $194\times$ more energy
efficient than PD-SOI MOSFET silicon neuron (MOSFET silicon neuron) and
$5\times10^{3}$ times more energy efficient than analog/digital circuit based
conventional neuron. Furthermore, the proposed L-BIMOS silicon neuron exhibits
spiking frequency in the GHz range, when the drain is biased at $V_{DG}$ = 2.0
V.
