Gate Modulation Effect in Nano-Scale Epitaxial Aluminum Films on Sapphire Substrate Grown by Molecular Beam Epitaxy

Electrical gating for modulating a wide variety of physical properties has enormous applications in semiconductor industry. The strong screening effect in metallic materials, in contrast, hinders them from being affected by applied field. In this work, we present the growth of high-quality epitaxial aluminum films by using molecular beam epitaxy. By scaling down the film thickness to a few nanometers, we have fabricated devices with 1-D and 2-D aluminum channels and observed resistance modulations by deploying the metal-insulator-metal stacked structure. The modulation effect, although quite weak, has been observed in almost all fabricated devices with reasonably small gate leakage. In this work, the correlation between the modulation effect, the film thickness, and the channel width will be discussed.