A method and system for improving planarization and uniformity of dielectric layers for providing improved optical efficiency in CCD and CMOS image sensor devices. In various embodiments, a dielectric planarization method for achieving better optical efficiency includes first depositing a first dielectric having an optically transparent property on and around a metal pattern. Optical sensors are formed in or on the substrate in areas between metal features. The metal pattern protects a sensor situated therebetween and thereunder from electromagnetic radiation. After the first dielectric layer is polished using CMP, a slanted or inclined surface is produced but this non-uniformity is eliminated using further planarization processes that produce a uniform total dielectric thickness for the proper functioning of the sensor.