Patent ID: 7977718
Filing Date: 2011-07-12
Classification: H01L

Abstract:
1. A pixel isolation and contact structure of a photodiode of a three-dimensional multi-layer image sensor in which a lower first conductive type material, a second conductive type material, and an upper first conductive type material are sequentially doped into silicon, forming one photodiode layer, the photodiode layer comprises one or more layers, and a transistor layer is formed at the highest layer or the lowest layer, the pixel isolation and contact structure comprises: an isolation type trench groove formed for pixel isolation; a plurality of contact type trench grooves respectively formed to a predetermined depth in order to connect circuits of photodiodes of each layer and the transistor layer; a sidewall insulating layer formed on sidewalls of the isolation type trench grooves and the contact type trench grooves; a first conductive type material sidewall layer formed within the sidewall insulating layer and having a structure in which the upper and lower first conductive type materials are interconnected to bury the second conductive type material; an insulating layer filled into the isolation type trench groove; a contact doped on a bottom surface of the contact type trench groove, for electrical connection with a corresponding photodiode; a conductive material filled into the contact type trench grooves; and a photodiode of a pinned structure formed in both directions of the second conductive type material through a thermal treatment process.