Ultra-Low Capacitance Spot PIN Photodiodes

Spot PIN photodiodes were integrated without any process modifications in a high-voltage 0.18 μm CMOS technology. These are combination of vertical and lateral using the P+ bulk wafer P-type ring at surface as anodes. Devices with N+ cathode N+/N-well compared. A small spot reduces capacitance to 1.47 fF leads 1.07 fF. The light sensitive area these is 707 2 . Simulated electric field distributions show full depletion photodiodes. Responsivities from 0.12 A/W 0.16 0.50 0.52 for 405 nm 675 nm, respectively, achieved. measured bandwidths 520 MHz 690 reverse biases 15 V 30 V.