Researchers from the University of Milano-Bicocca and other institutions in Italy and Germany have published a study in the Journal of Applied Physics exploring the impact of interface states and dielectric mismatch on the electrical properties of ultrathin silicon-on-insulator (SOI) films. These films are increasingly important in the semiconductor industry, including for energy-efficient electronic devices used in various energy sector applications.
The team, led by Andrea Pulici and Gabriele Seguini, investigated SOI films with varying thicknesses and dopant concentrations. They found that as the thickness of the SOI film decreased below 30 nanometers, the carrier concentration and electron mobility degraded. This degradation was attributed to non-passivated interface states at the silicon dioxide-silicon interface. The researchers demonstrated that high-temperature rapid thermal oxidation (RTO) could significantly mitigate these effects, improving the interface quality and electrical properties.
Furthermore, the study revealed that in samples with SOI thicknesses of 15 nanometers or less, the phosphorus ionization energy increased significantly at low temperatures. This increase was directly related to the dielectric mismatch between the silicon and the silicon dioxide. The researchers used a combination of techniques, including Time-of-Flight Secondary Ion Mass Spectrometry, Hall measurements, electron-paramagnetic resonance, and capacitance-voltage measurements, to characterize the samples and understand the underlying mechanisms.
The findings of this research have practical implications for the energy sector, particularly in the development of advanced semiconductor devices for energy conversion, storage, and efficient electronic systems. By understanding and controlling the interface states and dielectric mismatch in ultrathin SOI films, engineers can design more efficient and reliable devices for various energy applications.
This article is based on research available at arXiv.