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

• Published in: IEEE transactions on circuits and systems. II, Express briefs Express briefs, 2023-10, Vol.70 (10), p.1-1
• Main Authors: Kim, Dana, Hong, Jong-Phil, Lee, Jiwon, Nam, Jae-won
• Format: Article
• Language: English
• Subjects: Capacitance; CMOS; Detectors; Hardware security; High-speed optical techniques; junction capacitance; Junctions; light detector; Photodiodes; Quantum efficiency; Security circuit; shallow trench isolation; silicon photodiode; Voltage
• ISSN: 1549-7747; 1558-3791
• DOI: 10.1109/TCSII.2023.3289407

This article 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 × 50 μmtextsuperscript2. 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 × 1011 Jones, and noise equivalent power (NEP) of 8.599 × 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.