Electrical characterization of highly doped germanium nanowires using Hall bar configuration

Germanium (Ge) is the most compatible material with silicon-based complementary metal-oxide-semiconductor processes. Ge has a higher electron and hole mobility compared to Si, leading to improved device performance. Moreover, Ge nanowires (GeNWs) are promising nanostructures for future nano- and optoelectronics due to their unique properties. In this work, ion implantation of phosphorous followed by flash lamp annealing (FLA) operated in millisecond time scale were used to fabricate highly-doped n-type Ge layer on insulator. Raman spectroscopy and Rutherford backscattering spectrometry were performed to characterize the crystallinity of the Ge layers after FLA. Subsequently, doped GeNWs were fabricated using electron beam lithography and inductively coupled plasma reactive ion etching. Electrical characterization of the GeNWs was conducted using a symmetric six-contact Hall bar configuration. The effect of nanowire width on transport parameters was investigated. Moreover, FLA were applied to fabricate NiGe alloy on highly doped Ge layer for low-resistance ohmic contacts.