Charge coupled image sensor with u-shaped gates

摘要

A method and apparatus of forming adjacent, non-overlapping CCD electrodes within an image sensing device such the electrodes are U-shaped. The device provided by the disclosed method employs a substrate with a gate dielectric layer formed on a surface of the substrate with a plurality of phases created within the CCD. A deposited silicon layer is placed on the surface of the CCD and a mask is used to cover areas other than the first set of electrodes. Etching takes places leaving the mask areas to the deposited silicon and a set of side walls to the remaining deposited silicon are then oxidized. A first set of electrodes by forming an electrode layer placed over the CCD. CMP is employed to remove remaining deposited silicon layer as well as portions of the electrode layer such that the side walls remain vertical portions to electrode layer remaining in the side walls. The process is then repeated by placing another electrode material layer and another CMP process leaving two sets of adjacent U-shaped gates.