Si/Ge1-xSnx/Si transistors with highly transparent Al contacts

We study the monolithic quasi-ohmic contact formation with single-elementary Alto Ge1-xSnx channel devices with various Sn concentrations between 0.5 % and 4 %. Thereby we investigate the influence of increasing Sn content on the electrical transport properties in field-effect transistors fora wide temperature range between 77 K and 400 K. At low temperatures, the devices exhibit improved performance metrics, promising for cryoCMOS applications. Compared to pure Ge control devices, the introduction of Sn into the channel leads to a 20 times increased on-current. Ina multi-gate architecture, we analyze the decoupled influence of the carrier injection through the metal-semiconductor junction and the channel conduction.