A Schottky barrier field-effect transistor platform with variable Ge content on SOI

• Published in: Solid-state electronics Vol. 230; p. 109221
• Main Authors: Fuchsberger, Andreas, Wind, Lukas, Pacheco-Sanchez, Aníbal, Aberl, Johannes, Brehm, Moritz, Vogl, Lilian, Schweizer, Peter, Sistani, Masiar, Weber, Walter M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2025
• Subjects: Electronic transport; Metal-semiconductor multi-heterojunction; Schottky barrier field-effect transistor; Silicon-Germanium; Metal-semiconductor multi-heterojunction; Schottky barrier field-effect transistor; Electronic transport; Silicon-Germanium
• ISSN: 0038-1101
• DOI: 10.1016/j.sse.2025.109221

•SiGe layers with varying Ge-content up to 75% grown by ultra-low temperature molecular beam epitaxy on SOI.•Detailed temperature-dependent electrical characterization up 398 K.•Identification of transport regimes and the barrier heights with a thermionic-emission-based model.•Enhanced on-states as well as the transparent, quasi-ohmic contact properties interesting for beyond-CMOS applications. Advancing SOI-based transistors with Ge-rich layers aims to increase device performance in terms of on-state operation and switching speed. Here, we investigate multi-heterojunction SiGe-based Schottky barrier FETs with Ge concentrations up to 75% by means of temperature- dependent electrical characterizations to identify the transport regimes and the effective barrier heights with a thermionic-emission-based model. Importantly, incorporating 33% Ge gives the best compromise for n- and p-type on-state symmetry. As the Ge concentration increases, the p-type on-state current becomes dominant, which is interesting for low-power p-type transistors.