High-Speed Light Detection Sensor for Hardware Security in Standard CMOS Technology

This brief presents a triple-times-sensitive light detection sensor. The proposed sensor performs faster initialization starting from a power-up sequence, caused by the additional delay-cell logic. Furthermore, the finger- and well-type photodiodes detect light more quickly than a conventional structure while occupying the same active area of
$50\times 50\,\,\mu { {m}} {^{\mathrm{ 2}}}$
. The finger-type structure photodiode demonstrates an external quantum efficiency (EQE) of 76%, responsivity (
${R}$
) of 0.336 A/W, specific detectivity
$({D}^{*})$
of
$5.814\times 10^{11}$
Jones, and noise equivalent power (NEP) of
$8.599\times 10^{-17}$
W with under 550 nm illumination at reverse bias of 1.8 V, which are derived from TCAD simulation results. Both prototype light detection sensor with finger- and well-type photodiodes are implemented in a 180 nm standard CMOS technology (1P6M) and achieved about 3 and 1.3 times faster light detection speed than the conventional structure in optical experiment.