Collection efficiency and charge transfer optimization for a 4-T pixel with multi n-type implants

In order to increase collection efficiency and eliminate image lag,multi n-type implants were introduced into the process of a pinned-photodiode.For the purpose of improving the collection efficiency, multi n-type implants with different implant energies were proposed,which expanded the vertical collection region. To reduce the image lag,a horizontal gradient doping concentration eliminating the potential barrier waalso formed by multi n-type implants.The simulation result shows that the collection efficien...