Influence of the chalcogen element on the filament stability in CuIn(Te,Se,S) 2 /Al 2 O 3 filamentary switching devices.

Research paper by Tareq T Ahmad, Wouter W Devulder, Karl K Opsomer, Matthias M MM Minjauw, Umberto U Celano, Thomas T Hantschel, Wilfried W Vandervorst, Ludovic L Goux, Gouri Sankar GS Kar, Christophe C Detavernier

Indexed on: 14 Apr '18Published on: 14 Apr '18Published in: ACS Applied Materials & Interfaces


In this paper, we report on the use of CuInX (X = Te, Se, S) as a cation supply layer in filamentary switching applications. Being used as absorber layers in solar cells, we take advantage of the reported Cu ionic conductivity of these materials to investigate the effect of the chalcogen element on filament stability. In-situ XRD showed material stability attractive for Back-End-Of-Line in semiconductor industry. When integrated in 580 μm diameter memory cells, more volatile switching was found at low compliance current using CuInS and CuInSe compared to CuInTe, which is ascribed to the natural tendency for Cu to diffuse back from the switching layer to the cation supply layer, to form energetically more preferred Cu-S and Cu-Se bonds. Low-current and scaled behavior was also confirmed using C-AFM. Hence, by varying the chalcogen element, a method is presented to modulate the filament stability.