Depolarization mitigated in ferroelectric Hf_(0.5)Zr_(0.5)O_(2)ultrathin films(<5 nm)on Si substrate by interface engineering  

作　　者：Se Hyun Kim Younghwan Lee Dong Hyun Lee Geun Hyeong Park Hyun Woo Jeong Kun Yang Yong Hyeon Cho Young Yong Kim Min Hyuk Park 

机构地区：[1]Department of Materials Science and Engineering,College of Engineering,Seoul National University,Seoul 08826,Republic of Korea [2]Research Institute of Advanced Materials,College of Engineering,Seoul National University,Seoul 08826,Republic of Korea [3]Inter-university Semiconductor Research Center,College of Engineering,Seoul National University,Seoul 08826,Republic of Korea [4]Pohang Accelerator Laboratory,Pohang University of Science&Technology,Pohang 790784,Republic of Korea

出　　处：《Journal of Advanced Ceramics》2024年第3期282-292,共11页先进陶瓷（英文）

基　　金：This study was supported by the National Research Foundation(NRF)grant,funded by the Ministry of Science and Information and Communication Technology of Korea(MSIT)(Nos.2022M3F3A2A01073562,2020R1C1C1008193,and 2021M3F3A2A02037889);Younghwan Lee acknowledges support from the NRF grant,funded by the MSIT(No.NRF2022R1A6A3A01086832).We would like to thank Editage(www.editage.co.kr)for editing and reviewing the English language in the manuscript.Experiments at PLS-II were supported in part by the Korean government MSIT and POSTECH.

摘　　要：(Hf,Zr)O_(2)offers considerable potential for next-generation semiconductor devices owing to its nonvolatile spontaneous polarization at the nanoscale.However,scaling this material to sub-5 nm thickness poses several challenges,including the formation of an interfacial layer and high trap concentration.In particular,a low-k SiO_(2)interfacial layer is naturally formed when(Hf,Zr)O_(2)films are directly grown on a Si substrate,leading to high depolarization fields and rapid reduction of the remanent polarization.To address these issues,we conducted a study to significantly improve ferroelectricity and switching endurance of(Hf,Zr)O_(2)films with sub-5 nm thicknesses by inserting a TiO_(2)interfacial layer.The deposition of a Ti film prior to Hf_(0.5)Zr_(0.5)O_(2)film deposition resulted in a high-k TiO_(2)interfacial layer and prevented the direct contact of Hf_(0.5)Zr_(0.5)O_(2)with Si.Our findings show that the high-k TiO_(2)interfacial layer can reduce the SiO_(2)/Si interface trap density and the depolarization field,resulting in a switchable polarization of 60.2μC/cm^(2)for a 5 nm thick Hf_(0.5)Zr_(0.5)O_(2)film.Therefore,we propose that inserting a high-k TiO_(2)interfacial layer between the Hf_(0.5)Zr_(0.5)O_(2)film and the Si substrate may offer a promising solution to enhancing the ferroelectricity and reliability of(Hf,Zr)O_(2)grown on the Si substrate and can pave the way for next-generation semiconductor devices with improved performance.

关 键 词：FERROELECTRIC charge trapping HAFNIA DEPOLARIZATION 

分 类 号：TM282[一般工业技术—材料科学与工程]