Linear Mode Avalanche Photodiode With 1-GHz Bandwidth Fabricated in 0.35- $\mu $ m CMOS

We present an avalanche photodiode (APD) with separate absorption and multiplication zone. The APD is fabricated in a 0.35-μm CMOS process using an epitaxial wafer. Due to its thick detection zone, this concept offers a high dynamic quantum efficiency and thus a high resulting dynamic responsivity. Measurements using a 670-nm laser source demonstrate a maximum responsivity of 1.8· 10
⁴
A/W at 5 nW and a maximum bandwidth of 1.02 GHz at 5-μW illumination power. A maximum responsivity bandwidth product of 269.7 GHz· A/W was found at 35 V reverse bias voltage and 5-nW optical power.