Capacitors and methods of making the same are disclosed herein. In one embodiment, a capacitor comprises a structure having first and second oppositely facing surfaces and a plurality of pores each extending in a first direction from the first surface towards the second surface, and each having pore having insulating material extending along a wall of the pore; a first conductive portion comprising an electrically conductive material extending within at least some of the pores; and a second conductive portion comprising a region of the structure consisting essentially of aluminum surrounding individual pores of the plurality of pores, the second conductive portion electrically isolated from the first conductive portion by the insulating material extending along the walls of the pores.