Image sensing device

An image sensing device comprising:

• a semiconductor substrate having a first surface and a second surface opposite to the first surface and including different portions for a pixel region including pixel structures and a pad region used to provide external electrical connections;
• a first pad metal layer formed over the first surface of the semiconductor substrate and located in the pad region;
• an anti-reflection layer formed over a first portion of the first pad metal layer to contact a top surface of the first pad metal layer;
• and
• a pad passivation layer formed over the first pad metal layer and the anti-reflection layer,
• wherein a second portion of the first pad metal layer is provided as a pad open region formed to expose the top surface of the first pad metal layer and an interface between the first pad metal layer and the anti-reflection layer are structured not to be exposed to an outside.