An integrated circuit structure includes a dielectric layer having an upper portion and a lower portion. The dielectric layer is either an inter-layer dielectric (ILD) or an inter-metal dielectric (IMD). A phase change random access memory (PCRAM) cell includes a phase change strip, wherein the phase change strip is on the lower portion and has a top surface lower than a top surface of the dielectric layer, and a bottom surface higher than a bottom surface of the dielectric layer. A first conductive column is electrically connected to the phase change strip. The first conductive column extends from the top surface of the dielectric layer down into the dielectric layer. A second conductive column is in a peripheral region. The second conductive column extends from the top surface of the dielectric layer down into the dielectric layer. The first conductive column and the second conductive column have different heights.