Semiconductor device including data storage structure and method of manufacturing data storage structure

A data storage structure comprising:

• a lower electrode;
• a dielectric layer on the lower electrode;
• and
• an upper electrode on the dielectric layer, the upper electrode including an upper electrode interfacial layer in contact with the dielectric layer, wherein
• the dielectric layer includes a metal compound having a crystalline phase and including a first metal,
• the dielectric layer further includes a phase control material located in an interfacial region of the dielectric layer, the interfacial region being in contact with the upper electrode interfacial layer,
• the phase control material includes a second metal or a metal nitride,
• the metal nitride includes the second metal, and
• the upper electrode interfacial layer comprises a third metal and at least one of oxygen and nitrogen,
• wherein the third metal comprises at least one of tin, molybdenum, niobium, tantalum, titanium, indium, nickel, cobalt, tungsten, ruthenium, zirconium and hafnium.