This work presents a charge transfer model for a multi-implant (graded) pinned-buried photodetector for high frame rate imaging applications. The model takes into account the initial charge of each implanted region which is divided into a large number of small areas and the maximum effective transit length of the far and near electrons by taking into account the fringing field effect due to graded implants under uniform illumination condition. The model predicts 1.5 μs for a single-implant and 500 ns for a three-implant photodetector for collection of 90% of the initial charge. The computed values agree well with the experimental results for a three-implant 70 μm × 45 μm photodetector measured at a rate of 10 6 frames/s with uniformly illuminated by 100 ns LED pulses.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering
- Charge transfer
- High frame rate image sensors
- Transit time