Plasma Enhanced Atomic Layer Deposited HfO 2 Ferroelectric Films for Non-volatile Memory Applications RAJESH KUMAR JHA , 1,2 PRASHANT SINGH, 1 MANISH GOSWAMI, 1 and B.R. SINGH 1 1.—Department of Electronics and Communication Engineering, Indian Institute of Information Technology-Allahabad, Allahabad, Uttar Pradesh 211015, India. 2.—e-mail: rajajha25@gmail.com For this proposed work, structural, electrical and ferroelectric properties of metal-insulator-silicon (MIS) and metal-insulator-metal (MIM) capacitors with different HfO 2 (5 nm, 10 nm, 15 nm, 20 nm) thicknesses deposited on silicon and TiN/Silicon were investigated. The structural properties such as crystallographic phase, grain size with composition and refractive index of the plasma enhanced atomic layer deposited HfO 2 film was measured by x-ray diffraction, field emission scanning electron microscopy with energy dispersive spectroscopy and multiple angle ellipsometry. Memory window, leakage cur- rent density, closed loop hysteresis, remnant polarization, coercive field volt- age, data retention time, endurance and breakdown voltage of the deposited film were the important measured electrical parameters. The MIS structure shows a maximum memory window of 4 V, and the MIM structure shows maximum remnant polarization of 4 lC/cm 2 for 10 nm HfO 2 layer. The structure shows data retention capability of more than 10 years and fatigue resistance for more than 10 12 read/write cycles. Key words: Data retention time, endurance, ferroelectric, HfO 2 , memory window, plasma enhanced atomic layer deposition INTRODUCTION Because of the continuous scaling of the gate dielectric, the production and commercialization of ferroelectric field effect transistors (FeFET) have been impeded without finding any suitable ferroelectric material. 1 FeFET fabricated using conventional fer- roelectric materials such as PZT and SBT were popular in the recent past, and these materials suffered from various limitations such as high thick- ness, poor thermodynamic stability with silicon, improper interface between silicon (Si) and ferroelec- tric (Fe), and Fe-Si diffusion. 2,3 An improper Fe-Si interface causes higher leakage current resulting in the higher power dissipation and reduced data reten- tion time in the ferroelectric devices. Later, the introduction of buffer layer in between silicon and ferroelectric improves the interface and played a pivotal role to minimize the leakage current by acting as a barrier to ferroelectric-silicon inter-diffusion and hence improves the memory window and data reten- tion time. 4,5 Alternatively, the same buffer layer does have some drawbacks in terms of the depolarization field and coercive field. 6,7 In order to replace the conventional ferroelectric material with the single dielectric layer that can fulfill all the requirements of the ferroelectric layers as the memory element and capacitor as well, new materials were explored. With evolved deposition and characterization techniques, it turns out to be possible to explore the distinguishing properties of the standard dielectric materials such as HfO 2 , ZrO 2 , and Al 2 O 3 . In recent years, HfO 2 deposited by atomic layer deposition (ALD) has been extensively studied to determine its crystalline phases and the primitive polymorphism. 8 Three crystalline phases were observed in the HfO 2 film, monoclinic at room temperature, tetragonal above 1700°C and cubic above 2600°C. 9 In 2011, Bo ¨scke et al. 10 demonstrated (Received August 13, 2019; accepted November 15, 2019) Journal of ELECTRONIC MATERIALS https://doi.org/10.1007/s11664-019-07840-0 Ó 2019 The Minerals, Metals & Materials Society