A photodiode device and the manufacturing method of the same are provided. The photodiode device includes a substrate; an epitaxy layer on the substrate, the epitaxy layer including a window layer and a cap layer on the window layer, the cap layer covering a portion of the window layer; and a patterned conductive layer on the cap layer, the patterned conductive layer being formed with a bottom area and a top area wherein the bottom area is greater than the top area.