Photodiode with ultra-shallow junction for high quantum efficiency CMOS image sensor and method of formation

摘要

A pinned photodiode with an ultra-shallow highly-doped surface layer of a first conductivity type and a method of formation are disclosed. The ultra-shallow highly-doped surface latter has a thickness of about 100 Angstroms to about 500 Angstroms and a dopant concentration of about 5×10¹⁷ atoms per cm³ to about 1×10¹⁹ atoms per cm³. The ultra-shallow highly-doped surface layer is formed by diffusion of ions from a doped layer into the substrate or by a plasma doping process. The ultra-shallow pinned layer is in contact with a charge collection region of a second conductivity type.