Insulative-Collar Photodetector Structure for Lower Dark Current

The photodetector structure is segmented into distinct regions: a first doped semiconductor region, an intrinsic semiconductor region, and a second doped semiconductor region with opposite polarity. The insulative collar further segments the structure by laterally surrounding the intrinsic region and blocking dark current paths at the interface between the intrinsic region and the second doped region. This segmentation isolates the intrinsic region where photon detection occurs from the doped regions that generate dark current.

The insulative collar acts as an intermediary element positioned at the interface between the intrinsic semiconductor region and the second doped semiconductor region. It mediates the interaction between these regions by providing electrical insulation that blocks dark current while allowing the photodetector to maintain its PIN structure for photon detection. The collar material serves as a barrier that prevents harmful charge carrier generation at the interface.

The insulative collar serves as an intermediary barrier placed at the critical interface between the intrinsic and second doped semiconductor regions. This collar prevents direct contact between the intrinsic region and the heavily doped region, thereby blocking the generation of dark current at the interface while allowing the rest of the device to be manufactured using standard semiconductor fabrication processes.

The insulative collar is applied locally only at the specific interface region where dark current generation occurs, rather than throughout the entire device. This localized approach maintains the ease of manufacture by using targeted processing steps (such as selective deposition or etching) while addressing the specific problem of interface dark current without requiring complete redesign of the manufacturing process.