Avalanche photodiode image sensor in standard BiCMOS technology

To overcome the transistor-induced noise limitations of solid-state image sensors at low light levels, we investigate a programmable camera concept based on an image sensor that employs the avalanche effect for photogenerated charge carriers. Each pixel consists of an avalanche photodiode (APD), high-voltage stabilization circuitry, and image readout electronics. Special emphasis is placed on the integration and characterization of such an APD image sensor with an unmodified, commercially available BiCMOS process. Experimental results of the first APD camera in BiCMOS technology with 12/spl times/24 pixels shows individually programmable, stable diode gain up to a factor of 1000.