Image sensing devices and methods for fabricating the same

A method for fabricating an image sensing device, comprising:

• providing a first substrate having a first side and a second side opposing each other;
• forming a plurality of openings in the first substrate at the first side, wherein the openings define a plurality of active regions and cutting regions over the first substrate at the first side;
• forming a conductive via in the openings;
• forming a conductive pad over each of the conductive via in the openings, wherein the conductive pad overlies portions of the substrate in the active regions;
• forming a plurality of image sensing elements in the first substrate in the active regions at the first side;
• forming an internal structure in the active regions, overlying the image sensor elements and the conductive pad and electrically connecting the conductive pad, wherein the interconnect structure comprises color filters and interconnection features;
• forming a plurality of microlenses over the internal structure, substantially aligning with the image sensing elements;
• mounting a second substrate with the first substrate from the first side, wherein the second substrate is formed with a plurality of recesses therein and the recesses substantially align with the active regions, thereby forming cavities between the second substrate and the first substrate;
• performing a thinning process on the first substrate at the second side, exposing a surface of the conductive vias from the second side;
• forming a conductive layer over portions of the first substrate at the second side thereof, overlying each of the conductive vias and electrically connecting the conductive pad;
• and
• forming a conductive bump over a portion of the conductive layer.