Delamination and crack resistant image sensor structures and methods
A plurality of image sensor structures and a plurality of methods for fabricating the plurality of image sensor structures provide for inhibited cracking and delamination of a lens capping layer with respect to a planarizing layer within the plurality of image sensor structures. Particular image sensor structures and related methods include at least one dummy lens layer of different dimensions than active lens layer located over a circuitry portion of a substrate within the particular image sensor structures. Additional particular image sensor structures include at least one of an aperture within the planarizing layer and a sloped endwall of the planarizing layer located over a circuitry portion within the particular image sensor structures.
1. A method for fabricating an image sensor structure comprising:
providing a substrate including a photosensitive portion and a circuitry portion;
forming a dielectric isolated metallization stack located upon the substrate;
forming a planarizing layer over the dielectric isolated metallization stack;
forming a plurality of active lens layers located over the planarizing layer and registered with a plurality of photosensitive regions within the photosensitive portion, and forming at least one dummy lens layer of different dimensions at least in part over the planarizing layer and over the circuitry portion; and
forming a lens capping layer passivating exposed portions of the plurality of active lens layers, the at least one dummy lens layer and the planarizing layer.
2. The method of claim 1 further comprising forming a color filter layer over the dielectric isolated metallization stack prior to forming the planarizing layer over the dielectric isolated metallization stack, a plurality of color filter regions within the color filter layer also being registered with respect to the plurality of photosensitive regions.
3. The method of claim 1 wherein the forming the at least one dummy lens layer provides the at least one dummy lens layer with a different lens shape in comparison with the plurality of active lens layers.
4. The method of claim 1 wherein the forming the at least one dummy lens layer provides that the at least one dummy lens layer is coplanar at a bottom with the bottoms of the plurality of active lens layers.
5. The method of claim 1 wherein the forming the at least one dummy lens layer provides that the at least one dummy lens layer is not completely coplanar at a bottom with the bottoms of the plurality of active lens layers.
6. A method for fabricating an image sensor structure comprising:
providing a substrate including a photosensitive portion and a circuitry portion, wherein the circuitry portion includes a bonding pad;
forming a dielectric isolated metallization stack upon the substrate;
forming a planarizing layer over the dielectric isolated metallization stack, wherein the planarizing layer has a sloped endwall so that the planarizing layer does not extend over the bonding pad;
forming a plurality of active lens layers over the planarizing layer and registered with a plurality of photosensitive regions within the photosensitive portion;
forming a lens capping layer passivating exposed portions of the plurality of active lens layers and the planarizing layer.
7. The method of claim 6 further comprising forming a color filter layer over the substrate after forming the dielectric isolated metallization stack over the substrate and prior to forming the planarizing layer over the substrate, a plurality of color filter regions within the color filter layer also being registered with respect to the plurality of photosensitive regions.
8. The method of claim 6 wherein the planarizing layer includes at least two apertures formed over the circuitry portion.
9. The method of claim 6 , wherein by separating the planarizing layer from the bonding pad with the sloped endwall, the method reduces cracking and delamination of the image sensor structure when compared to image sensors having a planarization layer that extends over a bonding pad.
10. The method of claim 6 , wherein the bonding pad is present overlying one or more transistors, wherein the bonding pad is in electrical communication with at least one of the one or more transistors.
11. The method of claim 6 , wherein the sloped endwall forms an angle ranging from between 30 degrees and 80 degrees with respect to a horizontal surface.