A phase change device includes a substrate with a top surface. A heater structure is disposed on the substrate. The heater structure has first and second sidewalls on opposite sides of the heater structure. A phase change element is disposed over the heater structure. The phase change element includes three connected portions. A first portion is disposed over the heater structure. A second portion is disposed over the first sidewall of the heater structure. A third portion is over a first portion of the top surface of the substrate adjacent to and spaced apart from the first sidewall of the heater structure.