SiO2 doped Ge2Sb2Te5 thin films with high thermal efficiency for applications in phase change random accessmemory

Abstract

This study examined the various physical, structural and electrical properties ofSiO2 dopedGe2Sb2Te5 (SGST) films for phase change random access memory applications. Interestingly, SGSThad a layered structure (LS) resulting from the inhomogeneous distribution ofSiO2 after annealing. The physical parameters able to affect the reset current of phase change memory(Ires) were predicted from the Joule heating and heat conservation equations. WhenSiO2 was doped into GST, thermal conductivity largely decreased by ∼ 55%. Theinfluence of SiO2-doping on Ires was examined using the test phase change memory cell.Ires wasreduced by ∼ 45%. An electro-thermal simulation showed that the reduced thermal conductivitycontributes to the improvement of cell efficiency as well as the reduction ofIres, while the increased dynamic resistance contributes only to the latter. The formation andpresence of the LS thermal conductivity in the set state test cell after repeated switchingwas confirmed.