Phase change memory device having self-aligned bottom electrode and fabrication method thereof
View Patent ↗A semiconductor memory device and a fabrication method thereof capable of improving electric contact characteristic between an access device and a lower electrode are provided. The semiconductor memory device includes an access device formed in a pillar shape on a semiconductor substrate, a first conductive layer formed over the access device, a protection layer formed on an edge of the first conductive layer to a predetermined thickness, and a lower electrode connected to the first conductive layer.
1. A semiconductor memory device, comprising:
an access device formed in a pillar shape on a semiconductor substrate;
a first conductive layer formed over the access device;
a protection layer formed an edge of the first conductive layer to a predetermined thickness;
a lower electrode formed over the first conductive layer and electrically connected to the first conductive layer; and
a spacer formed over the protection layer to surround an outer circumference of the lower electrode.
2. The semiconductor memory device of claim 1 , wherein the protection layer is comprised of substantially the same material as the spacer.
3. The semiconductor memory device of claim 1 , wherein the protection layer includes a material having the same or similar etching properties as the spacer.