Self-aligned antiblooming structure for charge-coupled devices and method of fabrication thereof

摘要

A self-aligned element antiblooming structure for application to charge-coupled devices includes a region in the substrate in which the charge-coupled device is fabricated into which both a P and an N conductivity type impurity are introduced. By introducing impurities of different diffusivities, a sink region is created between two very narrow antiblooming barriers. Using appropriate process controls, the potential height of the antiblooming barriers may be adjusted to drain excess charge accmulating in the substrate adjacent the antiblooming barriers. In this manner the antiblooming function is accomplished using only a minimal area of the substrate. The invention is applicable to charge-coupled devices utilizing a variety of different clocking schemes, and to charge-coupled device image sensors using buried channels.