R&D: Exploration of Scandium Doping in SbTe for PCM Application

IEEE Transactions on Electron Devices has published an article written by Marinela Barci, Daniele Leonelli, Huawei Technologies Research and Development Belgium N.V., Leuven, Belgium, Xue Zhou, Xiaojie Wang, HiSilicon Technologies, Shenzhen, China, Daniele Garbin, Ganesh Jayakumar, Thomas Witters, Nathali Franchina Vergel, Shreya Kundu, Senthil Vadakupudhu Palayam, imec, Leuven, Belgium, Huifang Jiao, Hao Wu, HiSilicon Technologies, Shenzhen, China, and Gouri Sankar Kar, imec, Leuven, Belgium.

Abstract: “In this work, we fabricate and electrically demonstrate a 65-nm technology-compatible Phase change memory (PCM) pillar device using Sc-doped SbTe (ST) instead of GeSbTe (GST), for the first time fabricated on a 300-mm wafer in the 1T1R configuration. ST was chosen over GST to achieve a higher speed and endurance due to its faster crystallization speed and reduced volume variation during switching. Detailed knobs on how to improve stack in terms of CD, thickness (of electrode and chalcogenide material), and Sc doping are presented. The optimized stack shows ac switching from 300 ns to 1 μs for SET and RESET with current in the order of milliamperes and programming voltage less than 2.5 V. The endurance shows marginal memory window degradation up to 1E8 cycles and more than 1-h retention at 85° is achieved for the optimized stack of C:Si/50-nm ST:Sc 6%. The fabricated devices show the potential to extend the PCM technology toward high-speed storage class memory (SCM) applications.“