A phase changeable memory cell is disclosed. In an embodiment of the invention, a phase changeable memory cell is formed with an ultra-small contact area to reduce the programming current. This contact area between heater electrode and phase changeable material is limited by the thickness of thin films rather than lithographic critical dimension in one dimension. As a result, the contact area is much less than the square of lithographic critical dimension for almost every technology node, which is helps in reducing current. To further reduce the current and improve the heating efficiency, heater electrode is horizontally put with its length being tunable so as to minimize the heat loss flowing through the heater to the terminal that connects to the front end switch device. In addition, above and below the heater layer, low-thermal-conductivity material (LTCM) is used to minimize heat dissipation. This results in reduced power consumption of the phase changeable memory cell with improved reliability.