Reliability Study of 1T1C FeRAM Arrays With Hf<sub>0.5</sub>Zr<sub>0.5</sub>O₂ Thickness Scaling
Jun Okuno, Takafumi Kunihiro, Kenta KONISHI, Yusuke Shuto, Fumitaka Sugaya, Monica Materano, Tarek Ali, Maximilian Lederer, Kati Kuehnel, Konrad Seidel, Thomas Mikolajick, Uwe Schroeder, Masanori Tsukamoto, Taku Umebayashi
Abstract
We have reported that film thickness scaling of ferroelectric Hf0.5Zr0.5O2 (HZO) allows hafnium-based one-transistor and one-capacitor (1T1C) ferroelectric random-access memory (FeRAM) to obtain higher cycling tolerance for hard breakdown with lower voltage operation in prior reports. This paper is an extension of the previous works including a review of recent works on FeRAM-related devices from a film thickness scaling point of view. We experimentally verified the cycling tolerance advantage of film thickness scaling by 1T1C FeRAM array with different HZO thicknesses of 8 nm and 10 nm using different small capacitors areas (0.20, 0.40, and 1.00 lm2) at practical operation conditions for the first time, demonstrating higher reliability at the 8-nm sample with smaller capacitance area. To support the result, time zero dielectric breakdown (TZDB) and time dependent dielectric breakdown (TDDB) were conducted for both 8-nm and 10a-nm samples.