A pixel cell is formed by locating a first passivation layer over the final layer of metal lines. Subsequently, the uneven, non-uniform passivation layer is subjected to a planarization process such as chemical mechanical polishing, mechanical abrasion, or etching. A spin-on-glass layer may be deposited over the non-uniform passivation layer prior to planarization. Once a uniform, flat first passivation layer is achieved over the final metal, a second passivation layer, a color filter array, or a lens forming layer with uniform thickness is formed over the first passivation layer. The passivation layers can be oxide, nitride, a combination of oxide and nitride, or other suitable materials. The color filter array layer may also undergo a planarization process prior to formation of the lens forming layer. The present invention is also applicable to other devices.