Enhancement of Ferroelectricity in 5 nm Metal-Ferroelectric-Insulator Technologies by Using a Strained TiN Electrode

Cheng-Hung Wu; Kuan-Chi Wang; Yu-Yun Wang; Chenming Hu; Chun-Jung Su; Tian-Li Wu

doi:10.3390/nano12030468

Enhancement of Ferroelectricity in 5 nm Metal-Ferroelectric-Insulator Technologies by Using a Strained TiN Electrode

Nanomaterials (Basel). 2022 Jan 29;12(3):468. doi: 10.3390/nano12030468.

Authors

Cheng-Hung Wu¹, Kuan-Chi Wang¹, Yu-Yun Wang¹, Chenming Hu^{1

2}, Chun-Jung Su^{3

4}, Tian-Li Wu¹

Affiliations

¹ International College of Semiconductor Technology, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
² Department of Electrical Engineering and Computer Science, University of California, Berkeley, CA 94720, USA.
³ Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan.
⁴ Taiwan Semiconductor Research Institute, Hsinchu 30010, Taiwan.

Abstract

In this work, the ferroelectric characteristic of a 5 nm Hf_0.5Zr_0.5O₂ (HZO) metal-ferroelectric-insulator-semiconductor (MFIS) device is enhanced through strained complementary metal oxide semiconductor (CMOS)-compatible TiN electrode engineering. Strained TiN top-layer electrodes with different nitrogen (N) concentrations are deposited by adjusting the sputtering process conditions. The TiN electrode with 18% N exhibits a compressive characteristic, which induces tensile stress in a 5 nm HZO film. A device with 18% N in TiN shows a higher remanent polarization (2Pr) and larger capacitance value than the compared sample, indicating that the strained TiN is promising for enhancing the ferroelectricity of sub-5 nm HZO devices.

Keywords: HfZrO2; compressive; ferroelectric; strained TiN; sub-5 nm.