(Invited) Temperature Impact on Reliablity and Manufacturing of Embedded HfOx-Based RRAM: a Novel Pre-coding Method for Bypassing Soldering Reflow

This paper provides an overview of the temperature impact on the electrical behavior of oxide-based RRAM, during forming, low-field resistance reading, SET/RESET, disturb, data retention and endurance. HfO2-RRAM devices (in a 1T1R configuration) integrated in an advanced 65 nm technology are studied for this aim. We show that forming operation is strongly activated in temperature (i.e. -0.5 V per hundred Celsius degree), being much less for SET and RESET voltages (i.e. < -0.05 V per hundred Celsius degree); disturb of HRS at fixed voltage showed to be independent of temperature; endurance up to 3.10⁶ cycles, with optimized set of stress parameters showed no significant variation; data retention at 150 °C up to 68 days showed stable programming window, after different initial programming algorithms. After having overviewed the basic cell performances working under variable temperature, the issue of packaging thermal stress on HfOx-based RRAM cells will be analyzed in detail. Certain applications (for instance secure smartcards) require writing the content of information in memories before packaging. The thermal stress during this step poses serious troubles to the stability of the information in RRAM. The presentation will overview the different efforts that are spent on this topic, providing, for the first time in the literature, the results of data retention under 260°C up to 375°C (general temperature range experienced during packaging thermal stress) and innovative precoding methods to bypass the thermal issue associated to packaging.