An Overview of Ferroelectric Hafnia and Epitaxial Growth. Issue 5 (15th April 2021)

• Record Type: Journal Article
• Authors: Cao, Jing; Shi, Shu; Zhu, Yao; Chen, Jingsheng
• Other Names: Barabash Sergey V. guestEditor.; Fichtner Simon guestEditor.; Park Min Hyuk guestEditor.; Schenk Tony guestEditor.
• Is Part Of: Physica status solidi. Volume 15:Issue 5(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-04-15
• Subjects: epitaxial films -- ferroelectrics -- hafnia -- thin films; Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.202100025
• Languages: English
• ISSNs: 1862-6254

Abstract

Abstract : Hafnia thin films have been under intensive research during the past few years due to its robust ferroelectricity under very thin limit and good compatibility with silicon. The polar crystal structure critical to ferroelectricity in hafnia thin films is metastable, and is generally obtained in polycrystalline thin films, coexisting with other nonpolar phases. Recently, much attention has been focused on epitaxial ferroelectric hafnia thin films to get rid of the nonpolar phases, to investigate the more intrinsic factors to ferroelectricity, and its potential applications. Herein, recent progress on the growth of epitaxial hafnia thin films is reviewed. The epitaxial growth mechanism is explored, in particular, the interface matching, phase stability under temperature and oxygen pressure, followed by discussions on thickness dependency of ferroelectricity, and wake‐up effect in hafnia. Finally, an outlook on ferroelectric hafnia both on fundamental studies and future applications is discussed. Abstract : Epitaxial control of hafnia thin films can be effective while mediating the phase competition of monoclinic, orthorhombic, and rhombohedral phases. Therefore, the effects of growth temperature, epitaxial strain from substrate and bottom electrode, oxygen content, and film thickness variations are reviewed. Subsequent influences on ferroelectricity such as wake‐up effect, imprint, and retention are also discussed.