Author(s): Liu, ZY (Liu, Zhu-You); Zhang, CX (Zhang, Cai-Xin); Cao, RY (Cao, Ruyue); Cai, XF (Cai, Xuefen); Deng, HX (Deng, Hui-Xiong)

Source: PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS Article Number: 2200316 DOI: 10.1002/pssr.202200316 Early Access Date: OCT 2022

Abstract: Hf1-xZrxO2 alloy is recently employed as gate dielectric in complementary metal-oxide semiconductor (CMOS) devices because of its relatively low carrier trapping ability, low threshold voltage shift, and good reliability. Experimentally it is found that as the Zr concentration x increases, the device reliability caused by the defect-related electron trapping would be improved. However, the trap nature in Hf1-xZrxO2 alloy is still not yet well understood. Herein, using first-principles hybrid-functional calculations, the transition energies of some possible defects tending to occur in the experimental process for Hf1-xZrxO2 alloys are discussed. The results show that, differing from previous studies suggesting that the oxygen vacancy (V-O) is the main defect of electron trapping, the hydrogen interstitial (H-i), which can successfully explain the experimental observations of a reduction of the electron trapping ability as the Zr concentration increases, is more likely to be the origin responsible for the electron trapping in Hf1-xZrxO2 dielectric. This work, therefore, broadens the understanding of electron trapping effect in high-k dielectrics and gives guidance on improving the reliability in microelectronics.

Accession Number: WOS:000866387100001

ISSN: 1862-6254

eISSN: 1862-6270

Full Text: https://onlinelibrary.wiley.com/doi/10.1002/pssr.202200316