A phase change random access memory (PCRAM) device includes a memory cell overlying an inter-metal dielectric (IMD) layer, a protection coating, and a first sidewall spacer. The memory cell includes a bottom electrode, a top electrode and a phase change element between the top electrode and the bottom electrode. The protection coating is on an outer sidewall of the phase change element. The first sidewall spacer is on an outer sidewall of the protection coating. The first sidewall spacer has a greater nitrogen atomic concentration than the protection coating. The protection coating forms a first interface with the phase change element. The first interface has a first slope at a first position and a second slope at a second position higher than the first position, the second slope is different from the first slope.