Methods of forming a microlens array over a substrate employing a CMP stop

Abstract

A method of forming a microlens structure is provided along with a CCD array structure employing a microlens array. An embodiment of the method comprises providing a substrate having a surface with photo-elements on the surface; depositing a transparent material overlying the surface of the substrate; depositing a CMP stop overlying the transparent material; depositing a lens-shaping layer overlying the CMP stop layer; depositing and patterning a photoresist layer overlying the lens-shaping layer to form openings to expose the lens-shaping layer; introducing a first isotropic etchant into the openings and etching the lens-shaping layer where exposed to form initial lens shapes having a radius; stripping the photoresist; exposing the lens-shaping layer to a second isotropic etchant to increase the radius of the lens shapes; transferring the lens shape through the CMP stop layer into the transparent material using an anisotropic etch; and depositing a lens material overlying the transparent material, whereby the lens shapes are at least partially filled with lens material. Planarizing the lens material using CMP and stopping at the CMP stop layer.

Dependencies are inferred from the claim text.