An image sensor includes a plurality of photodiodes disposed in a semiconductor material to convert image light into image charge, and a metal grid, including a metal shield that is coplanar with the metal grid, disposed proximate to a backside of the semiconductor material. The metal grid is optically aligned with the plurality of photodiodes to direct the image light into the plurality of photodiodes, and a contact pad is disposed in a trench in the semiconductor material. The contact pad is coupled to the metal shield to ground the metal shield.