Improved Ferroelectric Properties in Hf0.5Zr0.5O2 Thin Films by Microwave Annealing

Biyao Zhao; Yunting Yan; Jinshun Bi; Gaobo Xu; Yannan Xu; Xueqin Yang; Linjie Fan; Mengxin Liu

doi:10.3390/nano12173001

Improved Ferroelectric Properties in Hf_0.5Zr_0.5O₂ Thin Films by Microwave Annealing

Nanomaterials (Basel). 2022 Aug 30;12(17):3001. doi: 10.3390/nano12173001.

Authors

Biyao Zhao^{1

2}, Yunting Yan³, Jinshun Bi^{1

2}, Gaobo Xu¹, Yannan Xu^{1

2}, Xueqin Yang^{1

2}, Linjie Fan^{1

2}, Mengxin Liu^{1

2

4}

Affiliations

¹ Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China.
² College of Integrated Circuits, University of Chinese Academy of Sciences, Beijing 100049, China.
³ Boston University, Boston, MA 02215, USA.
⁴ Beijing Zhongke New Micro Technology Development Co., Ltd., Beijing 100029, China.

Abstract

In the doped hafnia(HfO₂)-based films, crystallization annealing is indispensable in forming ferroelectric phases. In this paper, we investigate the annealing effects of TiN/Hf_0.5Zr_0.5O₂/TiN metal-ferroelectric-metal (MFM) capacitors by comparing microwave annealing (MWA) and rapid thermal annealing (RTA) at the same wafer temperature of 500 °C. The twofold remanent polarization (2Pr) of the MWA device is 63 µC/cm², surpassing that of the RTA device (40 µC/cm²). Furthermore, the wake-up effect is substantially inhibited in the MWA device. The orthorhombic crystalline phase is observed in the annealed HZO films in the MWA and RTA devices, with a reduced TiN and HZO interdiffusion in MWA devices. Moreover, the MFM capacitors subjected to MWA treatment exhibit a lower leakage current, indicating a decreased defect density. This investigation shows the potential of MWA for application in ferroelectric technology due to the improvement in remanent polarization, wake-up effect, and leakage current.

Keywords: TiN/Hf0.5Zr0.5O2/TiN film; ferroelectricity; leakage current; remanent polarization (Pr); wake-up effect.

Abstract

Grants and funding