Unravelling the nanoscale mechanism of polarization reversal in a HfZrO-based ferroelectric capacitor by vector piezoresponse force microscopy.

Ferroelectricity is in demand in many device concepts in electronics, energy and microsystem engineering. The performance of ferroelectrics-based devices is determined by either out-of-plane or in-plane polarization, or out-of-plane or in-plane piezoelectric strain. Real prospects for the practical implementation of innovative devices opened up after the discovery of ferroelectricity in ultrathin hafnium oxide films, due to their perfect compatibility with silicon technology.

Giant Electromechanical Effect in Piezoelectric Nanomembranes Based on HfZrO.

Since ultrathin ferroelectric HfO films can be conformally grown by atomic layer deposition even on complex three-dimensional structures, new horizons in the development of next-generation piezoelectric devices are opened. However, hafnium oxide has a significant drawback for piezoelectric applications: its piezoelectric coefficients are much smaller than those of classical materials currently used in piezoelectric devices. Therefore, new approaches to the development of high-performance piezoelectric devices based on exploiting the unique properties of HfO are of paramount importance.

Effect of Domain Structure and Dielectric Interlayer on Switching Speed of Ferroelectric HfZrO Film.

The nanosecond speed of information writing and reading is recognized as one of the main advantages of next-generation non-volatile ferroelectric memory based on hafnium oxide thin films. However, the kinetics of polarization switching in this material have a complex nature, and despite the high speed of internal switching, the real speed can deteriorate significantly due to various external reasons. In this work, we reveal that the domain structure and the dielectric layer formed at the electrode interface contribute significantly to the polarization switching speed of 10 nm thick HfZrO (HZO) film.

Wake-Up Free Ultrathin Ferroelectric HfZrO Films.

The development of the new generation of non-volatile high-density ferroelectric memory requires the utilization of ultrathin ferroelectric films. The most promising candidates are polycrystalline-doped HfO films because of their perfect compatibility with silicon technology and excellent ferroelectric properties. However, the remanent polarization of HfO films is known to degrade when their thickness is reduced to a few nanometers.

Temperature-Dependent Structural and Electrical Properties of Metal-Organic CVD MoS Films.

Metal-Organic CVD method (MOCVD) allows for deposition of ultrathin 2D transition metal dichalcogenides (TMD) films of electronic quality onto wafer-scale substrates. In this work, the effect of temperature on structure, chemical states, and electronic qualities of the MOCVD MoS films were investigated. The results demonstrate that the temperature increase in the range of 650 °C to 950 °C results in non-monotonic average crystallite size variation.