Analysis by simulation of amorphization current in phase change memory applied to pillar and GST confined type cells

• Published in: Microelectronic engineering Vol. 88; no. 5; pp. 827 - 832
• Main Authors: Cueto, O., Jahan, C., Sousa, V., Nodin, J.F., Syoud, S., Perniola, L., Fantini, A., Maitrejean, S., Toffoli, A., de Salvo, B., Boulanger, F.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-05-2011; Elsevier
• Subjects: Amorphization; Amorphization current; Applied sciences; Computer simulation; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Crystal structure; Design. Technologies. Operation analysis. Testing; Devices; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Electronics; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; Integrated circuits; Integrated circuits by function (including memories and processors); Mathematical analysis; Optimization; Optimized structures; PCRAM; Phase change; Physics; Pillars; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Specific phase transitions; Structural transitions in nanoscale materials; TCAD simulation; Amorphization current; Optimized structures; TCAD simulation; PCRAM; Cell structure; Amorphous material; Electrical conductivity; Circuit design; Amorphization; Random access memory; Cellular material; Amorphous state; Pulse code modulation; Phase transitions; Optimization; Optimal design; Crystalline material; Non volatile memory; Integrated circuit; Analytical method; PCM material; Thermal model; Computer aided design; Drift mobility
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2010.09.022

In this work comparative simulations and analysis of amorphization current are presented for pillar type and GST confined type PCRAM structures. The simulations are realized with the PCM model of Sentaurus Device using an analytical phase transition model coupled with a drift–diffusion electro-thermal model for the transport. The objectives of this work are the selection of optimized cell structures for reset conditions. It is confirmed that regarding
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reset the GST confined cell is more efficient than the pillar type. Our study points out that a compromise has to be found in some devices where the conditions of an optimized amorphous current correspond to a lowered resistivity contrast between the amorphous and crystalline states. A compromise has also to be found between optimal structures as designed by simulation and technological constraints associated to their fabrication.