학술논문
Polarization and Reliability Enhancement for Ferroelectric Capacitors by Interface Engineering Through Crystalline TaN
Document Type
Periodical
Source
IEEE Transactions on Electron Devices IEEE Trans. Electron Devices Electron Devices, IEEE Transactions on. 71(5):3433-3438 May, 2024
Subject
Language
ISSN
0018-9383
1557-9646
1557-9646
Abstract
A stack formed by consecutive deposition of 2 nm TaN/10 nm HfZrOx (HZO)/2 nm TaN in an ALD tool was proposed to be sandwiched between thick PVD TiN as the promising structure for ferroelectric capacitors (FeCAPs). Compared to the ALD TiN counterpart, ALD TaN exhibits a smaller coefficient of thermal expansion and a reduced lattice misfit between the electrode and HZO, enhancing remanent polarization (Pr). Additionally, ALD TaN demonstrates a larger barrier height with respect to HZO, contributing to improved reliability. The advantages of ALD-TaN FeCAPs over ALD-TiN FeCAPs are evidenced by a large operating field of 2.75 MV/cm for a 10-year lifetime with improvement of 0.15 MV/cm, a high 2Pr value of 38 $\mu \text{C}$ /cm2 with enhancement by 26.6%, and robust endurance of $3\times 10^{{10}}$ cycles with extension by 100X. The process holds the great potential to implement FeCAPs for high-reliability storage applications in AI era.