Can conventional phase-change memory devices be scaled down to single-nanometre dimensions?
IOP Publishing: Hybrid Open Access
Reason for embargo
The scaling potential of “mushroom-type” phase-change memory devices is evaluated, down to singlenanometre dimensions, using physically realistic simulations that combine electro-thermal modelling with a Gillespie Cellular Automata phase-transformation approach. We found that cells with heater contact sizes as small as 6 nm could be successfully amorphized and re-crystallized (RESET and SET) using moderate excitation voltages. However, to enable the efficient formation of amorphous domes during RESET in small cells (heater contact diameters of 10 nm or less), it was necessary to improve the thermal confinement of the cell to reduce heat loss via the electrodes. The resistance window between the SET and RESET states decreased as the cell size reduced, but it was still more than an order of magnitude even for the smallest cells. As expected, the RESET current reduced as the cells got smaller; indeed, RESET current scaled with the inverse of the heater contact diameter and ultra-small RESET currents of only 19 μA were achieved for the smallest cells. Our results show that the conventional mushroom-type phase-change cell architecture is scalable and operable in the sub-10nm region.
HH would like to thank the College of Engineering, Mathematics and Physical Sciences at the University of Exeter for PhD studentship funding while carrying out this work. CDW would like to thank the EPSRC for funding via grant EP/M015130/1. The authors would also like to thank Dr. Karthik Nagareddy (University of Exeter) for helpful discussions during this work.
This is the author accepted manuscript. The final version is available from IOP Publishing via the DOI in this record.
Vol. 28, No. 3, 035202