In this paper, the impact of Al2 O3 incorporation on the electrical characteristics of the SrTiO3 (STO) metal-insulator-insulator (MIM) capacitor was studied. The Al2 O 3 -doped STO (STO: Al2 O3 =3:1) MIM provides a high capacitance density (14.6 fF/μ m2) and a very low leakage current density (9.2× 10-9 A/ cm2 at -1 V) at the same time. The significant enhancement of the conduction band offset and bandgap due to Al2 O3 incorporation reduces leakage current largely while maintaining the favorable properties of STO, such as a large high- κ value, a small temperature coefficient of capacitance, and paraelectricity (no fatigue or aging problem) in the operating temperature range of devices. Meanwhile, we also made a comparison among pure STO, Al2 O 3 -doped STO, and HfO2 -doped STO MIM capacitors. Results revealed that STO MIM and HfO2 -doped STO MIM capacitors both show higher capacitance densities, while the leakage current of the Al2 O3 -doped STO MIM is much lower than those of both the STO MIM and HfO2 -doped STO MIM capacitors, which meets the strict requirement of the International Technology Roadmap for Semiconductors 2018. Therefore, the excellent result suggests that the Al2 O3 -doped STO film is a potential candidate material for dynamic random access memory and radio-frequency applications.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry