Gettering of the metal impurities in image sensors: An evaluation of heated carbon implants

A number of schemes have been proposed in the literature to getter the metal impurities, which are detrimental to the device performance and yield (DPY), in silicon. These schemes vary from segregation based gettering, to extended defect clusters to magic denuded zones. While some of these are empirical and others being expensive to implement, they often contradict with each other. It is the purpose of this paper to propose a scheme that is simple and inexpensive yet firmly based on the principles governing effective gettering of the metal impurities. Further implant capability for sub-micron technology nodes is also discussed.