Integrated phase change memory cell projection liner and etch stop layer

An integrated circuit (IC) device fabrication method comprising:

• forming a projection liner layer upon a heating layer and upon a bottom electrode;
• forming a phase change material (PCM) layer upon the projection liner layer;
• forming a top electrode layer upon the PCM layer;
• forming a phase change material (PCM) stack upon the projection liner layer above the bottom electrode by etching away undesired PCM layer portions and undesired top electrode layer portions utilizing the projection liner layer as a first etch stop, the first etch exposing the projection liner layer outside of the PCM stack, the PCM stack comprising a phase change volume, of phase change material, and a top electrode;
• forming an encapsulation layer upon the exposed projection liner layer and upon the PCM stack;
• and
• forming an encapsulation spacer against sidewall(s) of the PCM stack by etching away undesired encapsulation spacer portions utilizing the projection liner layer as a second etch stop, the second etch re-exposing the projection liner layer outside of the encapsulation spacer.