Wafer fabrication ion implant charging - Impact on gate oxide breakdown

Process induced charging is not new in the wafer fabrication process. However, it is difficult to identify as test structures used cannot detect this problem effectively as these structures are not connected to large metal or polysilicon network for charge collection or if these structures are covered by thick photoresist. Ion implantation is a major process where charging poses a problem to the extent of transistor gate oxide breakdown or degradation. This will be presented along with their respective charging models. This breakdown is strongly influenced by device design layout, implanter energy and diffusion breakdown strengths.