Antiferroelectric Hf0.25Zr0.75O2 With Ferroelectric Properties and Low Voltage Operation of AFeRAM and AFeFET by Using Low-Temperature Atomic Layer Deposition

A novel method had been demonstrated to induce antiferroelectric (AFE) HZO with 75% Zr concentrations to become ferroelectric (FE) properties by using low-temperature (150 °C) atomic layer deposition (ALD), confirmed by GI-XRD at 35.5°, indicating a higher orthorhombic phase content in the thin film. The TEM results showed that large grain size, representing less grain boundary, can reduce leakage current and improve the device gate controllability and reliability. AFE random access memory (AFeRAM) and AFE field-effect transistor (AFeFET) fabricated by this approach exhibited robust endurance performance with 109 cycles and 106 cycles, respectively, with proper initial memory windows. Note that the endurance test for AFeFET was conducted by 2.5 V pulse height and 500 ns pulsewidth, achieving low power consumption and high switching response. These findings suggest that using low-temperature ALD has significant potential as a viable approach for fabricating nonvolatile memory (NVM) devices with antiferroelectric HZO or AFE HZO.