A phase change material may be formed within a trench in a first layer to form a damascene memory element and in an overlying layer to form a threshold device. Below the first layer may be a wall heater. The wall heater that heats the overlying phase change material may be formed in a U-shape in some embodiments of the present invention. The phase change material for the memory element may be elongated in one direction to provide greater alignment tolerances with said heater and said threshold device.