High Capacitance Density and Thermal Leakage Improvement by Using High- κ Al2O3-Doped SrTiO3 MIM Capacitors

Abstract

In this paper, the impact of incorporation on the electrical characteristics of the (STO) metal–insulator–insulator (MIM) capacitor was studied. The -doped STO MIM provides a high capacitance density and a very low leakage current density at the same time. The significant enhancement of the conduction band offset and bandgap due to 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, -doped STO, and -doped STO MIM capacitors. Results revealed that STO MIM and -doped STO MIM capacitors both show higher capacitance densities, while the leakage current of the -doped STO MIM is much lower than those of both the STO MIM and -doped STO MIM capacitors, which meets the strict requirement of the International Technology Roadmap for Semiconductors 2018. Therefore, the excellent result suggests that the -doped STO film is a potential candidate material for dynamic random access memory and radio-frequency applications.