US Patent 11538988 Memory device with multi-layer liner structure

A memory cell design is disclosed. The memory cell structure includes phase change and selector layers stacked between top and bottom electrodes. An ohmic contact may be included between the phase change and selector layers. A multi-layer liner structure is provided on sidewalls of the phase change layer. In some such cases, the liner structure is above and not on sidewalls of the selector layer. The liner structure includes a first dielectric layer, and a second dielectric layer on the first dielectric layer. The liner structure includes a third dielectric layer on the second dielectric layer and that is sacrificial in nature, and may not be present in the final structure. The second dielectric layer comprises a high-k dielectric material or a metal silicate material. The second dielectric layer protects the phase change layer from lateral erosion and physical vertical etch and provides etch selectivity during the fabrication process.