Fabrication characterization of hafnium oxide thin films. (2019)

• Record Type: Journal Article
• Authors: Tongpeng, Suparat; Makbun, Kornwipha; Peanporm, Panadda; Sangkorn, Rattiyawan; Namsar, Orapim; Janphuang, Pattanapong; Pojprapai, Soodkhet; Jainsirisomboon, Sukanda
• Is Part Of: Materials today. Volume 17:Part 4(2019)
• Page Start: 1555
• Page End: 1560
• Publication Date: 2019
• Subjects: Hafnium oxide -- thin film -- sol-gel -- spin coating; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2019.06.181
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: Ferroelectric materials are commonly used in electronic devices such as memories, transistors, capacitors, sensors and actuators. Lead zirconate titanate (Pb(Zr1- x Ti x )O3 or PZT)-based ferroelectrics are a popular material for these applications due to their large dielectric constant, high polarization responses and superior piezoelectric properties. However, they contain toxic lead. Currently, the industry is looking for new ferroelectric materials with excellent electrical properties materials and that are also environmentally friendly. Hafnium oxide (Hafnai or HfO2 )-based materials have become attractive candidates because they are a simple binary oxide (non-perovskite structure) but exhibit ferroelectric properties and do not pollute to the environment. Therefore, this work aims to fabricate HfO2 thin films by using a sol-gel method. The mole ratio of nitric acid (HNO3 ) and deionized water (DI) was varied between 0.03:0.05, 0.05:0.05, and 0.10:0.05. After the spin-coated, thin films were annealed at 700, 800, and 900 °C for 3 hours. In addition, phase formation and microstructure of HfO2 thin films were also investigated by using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques, respectively. XRD investigation suggested that the HfO2 thin films with 0.03:0.05 and 0.05:0.05 mole ratios exhibited a monoclinic phase. In addition, a homogenous surface was found in all compositions. The experimental results implied that the mole ratio of HNO3 :DI water and annealing temperatures played a significant role in the formation of the HfO2 thin films.