Abstract: An integrated circuit structure includes a package component, which further includes a non-porous dielectric layer having a first porosity, and a porous dielectric layer over and contacting the non-porous dielectric layer, wherein the porous dielectric layer has a second porosity higher than the first porosity. A bond pad penetrates through the non-porous dielectric layer and the porous dielectric layer. A dielectric barrier layer is overlying, and in contact with, the porous dielectric layer. The bond pad is exposed through the dielectric barrier layer. The dielectric barrier layer has a planar top surface. The bond pad has a planar top surface higher than a bottom surface of the dielectric barrier layer.

Abstract: A method for forming a backside illuminated photo-sensitive device includes forming a gradated sacrificial buffer layer onto a sacrificial substrate, forming a uniform layer onto the gradated sacrificial buffer layer, forming a second gradated buffer layer onto the uniform layer, forming a silicon layer onto the second gradated buffer layer, bonding a device layer to the silicon layer, and removing the gradated sacrificial buffer layer and the sacrificial substrate.