Ferroelectric-HfO2/oxide interfaces, oxygen distribution effects, and implications for device performance

Atomic-scale understanding of HfO2 ferroelectricity is important to help address many challenges in developing reliable and high-performance ferroelectric HfO2 (fe-HfO2) based devices. Though investigated from different angles, a factor that is real device-relevant and clearly deserves more attentio...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Applied physics letters 2022-01, Vol.120 (1)
Hauptverfasser: Zhao, Shihui, Li, Bowen, Guo, Yuzheng, Li, Huanglong
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Atomic-scale understanding of HfO2 ferroelectricity is important to help address many challenges in developing reliable and high-performance ferroelectric HfO2 (fe-HfO2) based devices. Though investigated from different angles, a factor that is real device-relevant and clearly deserves more attention has largely been overlooked by previous research, namely, the fe-HfO2/dielectric interface. Here, we investigate the electronic structures of several typical interfaces formed between ultrathin fe-HfO2 and oxide dielectrics in the sub-3-nm region. We find that interface formation introduces strong depolarizing fields in fe-HfO2, which is detrimental for ferroelectric polarization but can be a merit if tamed for tunneling devices, as recently demonstrated. Asymmetric oxygen distribution-induced polarity, intertwined with ferroelectric polarization or not, is also investigated as a relevant interfacial effect in the real device. Though considered detrimental from certain aspects, such as inducing build-in field (independent of ferroelectric polarization) and exacerbating depolarization (intertwined with ferroelectric polarization), it can be partly balanced out by other effects, such as annealing (extrinsic) and polarity-induced defect formation (intrinsic). This work provides insights into ferroelectric-HfO2/dielectric interfaces and some useful implications for the development of devices.
ISSN:0003-6951
1077-3118
DOI:10.1063/5.0074332