An image sensor device and a method for manufacturing the image sensor device are provided. An image sensor device includes a pixel region and a non-pixel region in a substrate. In the pixel region there is a plurality of sensor elements. The non-pixel region is adjacent to the pixel region and has no sensor element. Dielectric grids are disposed in the pixel region with a first dielectric trench between two adjacent dielectric grids. The first dielectric trench aligns to a respective sensor element. Second dielectric trenches are disposed in the non-pixel region.