The invention provides a chip package and fabrication method thereof. In one embodiment, the chip package includes: a semiconductor substrate having opposite first and second surfaces, at least one bond pad region and at least one device region; a plurality of conductive pad structures disposed on the bond pad region at the first surface of the semiconductor substrate; a plurality of heavily doped regions isolated from one another, underlying and electrically connected to the conductive pad structures; and a plurality of conductive bumps underlying the heavily doped regions and electrically connected to the conductive pad structures through the heavily-doped regions.