Thermal-stability optimization of Al2O3/Cu-Te based conductive-bridging random access memory systems

被引：25

作者：

Goux, L. ^{[1
]}

Opsomer, K. ^{[1
]}

Franquet, A. ^{[1
]}

Kar, G. ^{[1
]}

Jossart, N. ^{[1
]}

Richard, O. ^{[1
]}

Wouters, D. J. ^{[1
,2
]}

Muller, R. ^{[1
]}

Detavernier, C. ^{[3
]}

Jurczak, M. ^{[1
]}

Kittl, J. A. ^{[1
]}

机构：

[1] IMEC, B-3001 Louvain, Belgium

[2] Katholieke Univ Leuven, ESAT, B-3001 Louvain, Belgium

[3] Univ Ghent, B-9000 Ghent, Belgium

来源：

THIN SOLID FILMS | 2013年 / 533卷

关键词：

CBRAM; ECM; Cu-Te; Phase stability; Microstructure; Elemental diffusion; Buffer layer;

D O I：

10.1016/j.tsf.2012.10.103

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

In this article we study the thermal stability of Al2O3\Cu-Te bi-layers up to temperatures used in the back-end-of-line integration process flow of conductive-bridging random-access-memory (CBRAM) technology. We investigate the temperature dependence of the microstructure and morphology of the CuxTe1-x layers for 0.2 < x < 0.8. For x > 0.7, phase separation is observed for as-deposited layers, resulting in rough morphology. Te-rich CuxTe1-x layers (x < 0.5) show large segregation processes during post-deposition annealing. Cu-Te phase restructuration phenomena are also observed during annealing in the range 0.5 < x < 0.7, however affecting little the roughness of the layer. On the other hand, both the Cu and Te elements diffuse into the Al2O3 layer already at moderate temperatures. These in-diffusion processes are efficiently reduced by inserting thin Ti layer at the Al2O3\Cu-Te interface. By means of secondary ion-mass spectroscopy analysis, we show that the thickness of the Ti layer allows obtaining either Cu-barrier (6 nm-thick Ti) or Cu-buffer (3 nm-thick Ti) properties. The optimized thermal stability achieved both by tuning the Cu-Te composition and by inserting 3 nm-thick Ti layer results in excellent and thermally stable CBRAM functionality after stack integration. (c) 2012 Elsevier B.V. All rights reserved.

引用

页码：29 / 33

页数：5

共 7 条

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