CMOS-compatible Hf_0.5Zr_0.5O₂-based ferroelectric memory crosspoints fabricated with damascene process

Area of Science:

• Materials Science
• Electrical Engineering
• Solid State Physics

Background:

• Ferroelectric materials are crucial for non-volatile memory.
• Hafnium Zirconium Oxide (HZO) is a promising ferroelectric material for advanced memory devices.
• Complementary Metal-Oxide-Semiconductor (CMOS) compatibility is essential for large-scale integration.

Purpose of the Study:

• To fabricate and characterize Hf0.5Zr0.5O2 (HZO) based ferroelectric memory crosspoints using a CMOS-compatible damascene process.
• To compare the performance of scaled crosspoint devices with larger benchmark devices.
• To investigate the endurance and switching speed of these novel memory structures.

Main Methods:

• Fabrication of HZO ferroelectric memory crosspoints via a CMOS-compatible damascene process.
• Plasma-enhanced atomic layer deposition (PEALD) of a 9 nm thick HZO ferroelectric thin film.
• Electrical characterization including endurance testing and switching time measurements.

Main Results:

• Crosspoint devices exhibited an order of magnitude improvement in endurance compared to benchmark devices.
• Switching times for scaled crosspoints were <170 ns, significantly faster than larger devices.
• All devices achieved a remnant polarization (2Pr) of ~50 µC cm-2 after 10^5 cycles.

Conclusions:

• Downscaled HZO ferroelectric memory crosspoints demonstrate superior endurance and switching speed.
• The CMOS-compatible damascene process enables high-performance ferroelectric memory fabrication.
• These findings highlight the potential of HZO crosspoints for advanced memory technologies.