A scalable ferroelectric non-volatile memory operating at high temperature

Non-volatile memory (NVM) devices that reliably operate at temperatures above 300 °C are not available commercially. Numerous emerging harsh environment applications, including aeronautics, space exploration, oil and gas exploration, nuclear power plants, mining, and more, demand complex in-situ computing and sensing capabilities, where high-temperature NVM plays a critical role. Current Silicon (Si)-based micro(nano)electronics, utilizing complementary metal oxide semiconductor (CMOS) technology, encounter reliability challenges above 150 °C and cannot retain their functional properties at high temperatures. Ferroelectric Al_xSc_1-xN exhibits strong potential for utilization in NVM devices operating at very high temperatures (> 500 °C) given its stable and high remnant polarization (P_R) above 100 μC/cm² with demonstrated ferroelectric transition temperature (T_C) > 1000 °C. Here, we demonstrate an Al_0.68Sc_0.32N ferroelectric diode based NVM device that can reliably operate with clear ferroelectric switching up to 600 °C with distinguishable On and Off states. The coercive field (E_C) from the Triangle Wave I-V measurements is found to be -5.84 (E_C-) and +5.98 (E_C+) (+/- 0.1) MV/cm at room temperature (RT) and found to decrease with increasing temperature up to 600 °C. The devices exhibit high remnant polarizations (> 100 μC/cm²) which are stable at high temperatures. At 600 °C, our devices show 1 million read cycles with On-Off ratio above 1 for > 60 hours. Finally, the operating voltages of our AlScN ferrodiodes are < 15 V at 600 °C which is compatible with Silicon Carbide (SiC) based high temperature logic technology, thereby making our demonstration a major step towards commercialization of NVM integrated high-T computers. NVM characteristics of engineered ferrodiodes with higher On-Off ratios at > 600 °C will also be presented in the meeting.