Reliability Study of 1T1C FeRAM Arrays With Hf<sub>0.5</sub>Zr<sub>0.5</sub>O₂ Thickness Scaling
oleh: 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
| Format: | Article |
|---|---|
| Diterbitkan: | IEEE 2022-01-01 |
Deskripsi
We have reported that film thickness scaling of ferroelectric Hf<sub>0.5</sub>Zr<sub>0.5</sub>O<sub>2</sub>(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 <inline-formula> <tex-math notation="LaTeX">$1.00~\mu\text{m}^{2}$ </tex-math></inline-formula>) 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.