Trench-defined charge-coupled device

摘要

A charge-coupled device (CCD) is formed by first defining relatively deep trenches having relatively small lateral dimensions in the surface of a silicon bulk region. A relatively thin silicon dioxide layer is formed over the silicon surface and inside each trench to cover the internal surfaces thereof. Finally, respective conducting electrode layers are formed over each trench covering the silicon dioxide layer within the trench. Such a CCD structure provides improved packing density and versatility of function over a conventional surface electrode CCD structures. When used in an image-sensing device, the trench-defined CCD structure provides improved quantum efficiency, owing to the deeper potential wells which may be formed in such structures for capturing photogenerated charge carriers.