Liu Huan, Peng Yue, Han Genquan, Liu Yan, Zhong Ni, Duan Chungang, Hao Yue
State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi'an, 710071, China.
Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai, China.
Nanoscale Res Lett. 2020 May 24;15(1):120. doi: 10.1186/s11671-020-03353-6.
This paper investigates the impacts of post-rapid thermal anneal (RTA) and thickness of ZrO on the polarization P and electrical characteristics of TaN/ZrO/Ge capacitors and FeFETs, respectively. After the RTA ranging from 350 to 500 °C, TaN/ZrO/Ge capacitors with 2.5 and 4 nm-thick amorphous ZrO film exhibit the stable P. It is proposed that the ferroelectric behavior originates from the migration of the voltage-driven dipoles formed by the oxygen vacancies and negative charges. FeFETs with 2.5 nm, 4 nm, and 9 nm ZrO demonstrate the decent memory window (MW) with 100 ns program/erase pulses. A 4-nm-thick ZrO FeFET has significantly improved fatigue and retention characteristics compared to devices with 2.5 nm and 9 nm ZrO. The retention performance of the ZrO FeFET can be improved with the increase of the RTA temperature. An MW of ~ 0.46 V is extrapolated to be maintained over 10 years for the device with 4 nm ZrO.
本文分别研究了快速热退火（RTA）后处理以及ZrO厚度对TaN/ZrO/Ge电容器和铁电场效应晶体管（FeFET）的极化P和电学特性的影响。在350至500°C的RTA处理后，具有2.5纳米和4纳米厚非晶ZrO薄膜的TaN/ZrO/Ge电容器表现出稳定的P。研究表明，铁电行为源于由氧空位和负电荷形成的电压驱动偶极子的迁移。具有2.5纳米、4纳米和9纳米ZrO的FeFET在100纳秒编程/擦除脉冲下表现出良好的记忆窗口（MW）。与具有2.5纳米和9纳米ZrO的器件相比，具有4纳米厚ZrO的FeFET的疲劳和保持特性得到了显著改善。ZrO FeFET的保持性能可随着RTA温度的升高而提高。对于具有4纳米ZrO的器件，预计约0.46伏的MW可在10年内保持。
