Heater system optimization for robust ePCM reliability and scalability in 28nm FDSOI technology

One of the most promising Embedded Phase Change Memory (ePCM) integration scheme is the wall architecture, which relies on the dedicated Heater element to thermally switch the device. A good control of this element is a key factor to satisfy the performance requirements of the automotive market. In this paper, the optimization of TiSiN Heater system in
$0.019\mu \mathrm{m}^{2}\text{ePCM}$
cell realized with 28nm FDSOI technology is extensively reported. Key fabrication parameters defining heating efficiency are investigated, covering a large range of Heater resistance. Their impact on
$e$
PCM reliability of elementary device and 16MB memory array, considering both retention and endurance, is characterized and the key role played by Heater is demonstrated, opening a path to scaled programming currents. Finally, TiSiN ALD deposition process is proposed as the solution to improve uniformity and scalability of Heater resistance. As Heater is the variable controlling the whole system, this approach guarantees the robustness of
$e$
PCM technology for automotive grade-0 applications.