(Hf,Zr)O2-based ferroelectrics: from fundamentals to applications

HfO2/ZrO2-based ferroelectrics have been referred to as “the ferroelectrics of the future”, because they retain their polar nature down to a few nanometers and are fully compatible with modern CMOS technology. However, their full application potential and fundamental science behind the formation of ferroelectricity are still being discovered.

Scope:

In the first years after the report of ferroelectricity in Si:HfO2 thin films, people with background in semiconductor industry immediately started investigating the potential of the materials for ferroelectric memories with both capacitor- and transistor-based concepts. As HfO2 and ZrO2 are already integrated as dielectrics in state-of-the-art devices, the idea of “simply making them ferroelectric” to establish a non-volatile memory device was highly attractive. A few years later, the potential for steep-slope transistors utilizing the negative-capacitance effect (NC-FETs) was recognized and formed today’s second major branch of application-driven research on the topic of fluorite-type ferroelectrics.

This very applied perspective, however, caused a much slower pace toward fundamental understanding of the formation of this ferroelectric behavior. Moreover, researchers with a strong background in ferroelectrics remained a bit skeptical at first as it was very surprising that such properties had been overlooked in such well-studied oxides. In recent years, the understanding solidified and the communities started interacting. Nonetheless, there is still a lot to be done, both theoretically and experimentally.

Meanwhile, applied research did not stop and further applications beyond the abovementioned memories and low-power logic devices have been suggested. Today, the range of applications is broad and includes neuromorphic computing, energy storage and energy harvesting, piezo- and pyroelectric devices in general, decoupling capacitors, microwave antennas, and phase shifters.

The aim of this symposium is to provide a platform:

• for people working on these material to gain insights into applications up to industrial level
• for applied and fundamental researchers to connect and exchange
• that serves as a step stone for people who consider starting to get engaged in this exciting and quickly growing new field

Hot topics to be covered by the symposium:

• Novel growth and fabrication schemes
• Fundamental insights from theory and experiments
• Electric field cycling behavior: root causes and solutions
• Negative-capacitance effect and NC-FETs
• Emerging ferroelectric memories (capacitors-based FRAM, FE-FETs, FTJs and novel concepts)
• Piezo- and pyroelectric properties and related applications
• Neuromorphics and further applications
• Application insights and viewpoints from industrial partners

• Cheol Seong Hwang (Seoul National University, South Korea): "Charge boosting in stacked ferroelectric/dielectric layers based on transient negative capacitance effect in (Hf,Zr)O2 film."
• Uwe Schroeder (NaMLab gGmbH, Germany): [Overview on Ferroelectric HfO2] 
• Evgeny Tsymbal (Univ. of Nebraska, United States): “Reversible spin texture in ferroelectric oxides” 
• Mircea Dragoman (National Institute for Research and Development in Microtechnologies - IMT Bucharest, Romania): "Microwave and THz devices using HfO2-based ferroelectrics"
• Takao Shimizu or Hiroshi Funakubo (Tokyo Institute of Technology, Japan): "Electric field driven phase changes in epitaxial HfO2-based ferroelectric films"
• Roozbeh Tabrizian (Univ. Florida): [M/NEMS: HfO2-based Acoustic Resonators] 
• Michael Hoffmann (NaMLab gGmbH, Germany): "Negative Capacitance in HfO2- and ZrO2-based materials"
• Alexei Gruverman (Univ. of Nebraska, United States): [Nanoscopic Insights into Electric Field Cycling Behavior.]
• Seung Chul Chae (Seoul National University, South Korea): "Stable Sub-Loop Behavior in Ferroelectric Si-Doped HfO2" 
• Alfred Kersch (Munich University of Applied Science, Gemany): "Characteristics of doped hafnia and zirconia from DFT calculations"
• Sanghun Jeon (KAIST, South Korea): "Non volatile ferroelectric tunnel junction  for neuromorphic  device application"

• Sabine Kolodinski (Globalfoundries Inc., Germany): [View from Industry and Report on their activities on NC-FETs, AFE-RAM, FeFET, Pyroelectric applications]
• Jaegil Lee (SK Hynix, South Korea): "Ferroelectric Device Applications & Challenges"
• Anders Blom (Synopsys Inc. United States): [Capabilities of a New Simulation Framework for Ferroic Materials] 
• Milan Pesic (Applied Materials Inc., United States): "Physical Mechanisms and Reliability of Ferroelectric Memories"
• Stefan Müller (Ferroelectric Memory GmbH, Germany):  [Ferroelectric HfO2 and its Impact on the Memory Landscape] 
• Shingo Yoneda (Murata Manufacturing Co. Ltd., Japan): "Nonlinear Polarization Response of HfO2-based Thin Films Fabricated by Chemical Solution Deposition"        
• Bert Jan Offrein (IBM Research Zurich, Switzerland): [Neuromorphic Devices Based on FE HfO2]