Fabrication of Electrospun Porous TiO2 Dielectric Film in a Ti–TiO2–Si Heterostructure for Metal–Insulator–Semiconductor Capacitors

• Published in: Micromachines (Basel) Vol. 15; no. 10; p. 1231
• Main Authors: Yoo, Jin-Uk, Choi, Tae-Min, Pyo, Sung-Gyu
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 30.09.2024; MDPI
• Subjects: Anatase; Annealing; Capacitors; Chemical vapor deposition; Dielectrics; Electrical properties; Electrospinning; electrospun dielectric layer; Experiments; Heterostructures; Leakage current; MIS; MIS (semiconductors); Polyvinylidene fluorides; Scanning electron microscopy; Silicon dioxide; Silicon wafers; Spectrum analysis; Temperature; Thin films; TiO2; Titanium dioxide; Vinylidene fluoride; South Korea; Germany
• ISSN: 2072-666X; 2072-666X
• DOI: 10.3390/mi15101231

The development of metal–insulator–semiconductor (MIS) capacitors requires device miniaturization and excellent electrical properties. Traditional SiO2 gate dielectrics have reached their physical limits. In this context, high-k materials such as TiO2 are emerging as promising alternatives to SiO2. However, the deposition of dielectric layers in MIS capacitors typically requires high-vacuum equipment and challenging processing conditions. Therefore, in this study, we present a new method to effectively fabricate a poly(vinylidene fluoride) (PVDF)-based TiO2 dielectric layer via electrospinning. Nano-microscale layers were formed via electrospinning by applying a high voltage to a polymer solution, and electrical properties were analyzed as a function of the TiO2 crystalline phase and residual amount of PVDF at different annealing temperatures. Improved electrical properties were observed with increasing TiO2 anatase content, and the residual amount of PVDF decreased with increasing annealing temperature. The sample annealed at 600 °C showed a lower leakage current than those annealed at 300 and 450 °C, with a leakage current density of 7.5 × 10−13 A/cm2 when Vg = 0 V. Thus, electrospinning-based coating is a cost-effective method to fabricate dielectric thin films. Further studies will show that it is flexible and dielectric tunable, thus contributing to improve the performance of next-generation electronic devices.