Evidence of the Thermo-Electric Thomson Effect and Influence on the Program Conditions and Cell Optimization in Phase-Change Memory Cells

Author

Castro, David Tio ; Goux, L. ; Hurkx, Godefridus Adrianus Maria ; Attenborough, K. ; Delhougne, R. ; Lisoni, J. ; Jedema, F.J. ; ´t Zandt, M.A.A. ; Wolters, Rob A. M. ; Gravesteijn, D.J. ; Verheijen, M. ; Kaiser, Marcus ; Weemaes, R.G.R.

Author_Institution

NXP-TSMC Res. center, Leuven

fYear

2007

fDate

10-12 Dec. 2007

Firstpage

315

Lastpage

318

Abstract

We present physical and electrical evidence of the Thomson thermo-electric effect in line-type phase-change memory cells. This causes a shift of the molten zone during RESET programming towards the anode contact, and as a consequence the phase change material (PCM) design at the contact area has a significant influence on the program conditions. First statistical studies showed a reduction of minimum Reset currents by ~5% and Set voltages by -28% when PCM extensions around the anode are used instead of fine line contacts. This Thomson effect remains important with further cell scaling.

Keywords

Thomson effect; optimisation; phase change materials; random-access storage; PCRAM; RESET programming; anode contact; cell optimization; molten zone shift; phase-change memory cells; thermo-electric Thomson effect; Anodes; Contacts; Current density; Differential equations; Electrodes; Phase change materials; Phase change memory; Phase change random access memory; Temperature; Thermal conductivity;

fLanguage

English

Publisher

ieee

Conference_Titel

Electron Devices Meeting, 2007. IEDM 2007. IEEE International

Conference_Location

Washington, DC

Print_ISBN

978-1-4244-1507-6

Electronic_ISBN

978-1-4244-1508-3

Type

conf

DOI

10.1109/IEDM.2007.4418934

Filename

4418934