Electrical and Mechanical Properties Enhancement in Superlattice‐Like GaSb/Ge2Sb2Te5 Phase Change Thin Films

Abstract

AbstractA 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)/Ge2Sb2Te5 (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 Ge2Sb2Te5 (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.