Current assisted avalanche photo diodes (CAAPDs) with separate absorption and multiplication region in conventional CMOS

A current assisted avalanche photodetector (CAAPD) is presented with a large detection window of 40 × 40 μm2, having a small 1-fF avalanche diode in its center. To quickly guide the photogenerated electrons to the center for avalanche multiplication, a drift field with associated majority hole current is applied across the neutral detection volume. This first type of CAAPD is fabricated in a conventional 350-nm CMOS process on a high resistive p− epi-layer. The low diode-junction capacitance can be of interest to integrated receivers. The CAAPD is characterized for its basic functionality, including the effects of lateral detection delay and gain.A current assisted avalanche photodetector (CAAPD) is presented with a large detection window of 40 × 40 μm2, having a small 1-fF avalanche diode in its center. To quickly guide the photogenerated electrons to the center for avalanche multiplication, a drift field with associated majority hole current is applied across the neutral detection volume. This first type of CAAPD is fabricated in a conventional 350-nm CMOS process on a high resistive p− epi-layer. The low diode-junction capacitance can be of interest to integrated receivers. The CAAPD is characterized for its basic functionality, including the effects of lateral detection delay and gain.