Data Retention Insights from Joint Analysis on BEOL-Integrated HZO-Based Scaled FeCAPs and 16kbit 1T-1C FeRAM Arrays

Extensive data retention measurements are performed on HZO-based BEOL-integrated scaled ferroelectric capacitors (FeCAPs) and 16kbit 1T-1C FeRAM arrays for the first time. At FeCAP level, Opposite State (OS) retention is strongly degraded by imprint phenomenon occurring during bake with a 0.20eV activation energy (EA) and affecting equally ‘0’ and ‘1’ states. Imprint is found to be write-voltage independent, showing great promises for FeRAM voltage scaling with adequate write and read voltages distinction. At FeRAM-array level, post-bake distributions are reconstructed. Same-State (SS) and OS drifts of both logic states along bake time and temperature are consistent with FeCAP data (EA = 0.19eV). These drifts are attributed to imprint and are demonstrated to be partly recoverable through bipolar cycling at operating voltage.