Electrical and Mechanical Properties Enhancement in Superlattice‐Like GaSb/Ge 2 Sb 2 Te 5 Phase Change Thin Films

A promising phase change materials based on a distinct nanoscale structure called superlattice is applied in lateral phase change memory (PCM) due to comprehensive performances. In this work, superlattice‐like structure of [GaSb( x )/Ge 2 Sb 2 Te 5 ( y )] n ( x  = 6,9,12,18 nm; y  = 12,18 nm; n  = 3,6) thin films is proposed and alternatively deposited with GaSb and Ge 2 Sb 2 Te 5 (GST) layers by magnetron sputtering method. The experimental results show that [GaSb( x nm)/GST(12 nm)] 3 thin films possess higher crystallization temperature and less volume change than that of monolayer GST. Moreover, [GaSb( x )/GST(12)] 3 thin films show super‐hardness and super‐modulus effect. The hardness enhancement mechanism is discussed and the critical thickness of GST layer is calculated as ≈18.1 nm, thus the interfaces are coherent without dislocation threading in critical condition. Therefore, the higher thermal stability and increased hardness values reflect great potential in practical application of superlattice‐like [GaSb( x )/GST(12)] n thin films.