We demonstrate Fermi-level unpinning and contact resistance reduction by surface passivation using SF6 plasma treatment of a metal/germanium (Ge) contact. A specific contact resistivity (ρc) of 1.14 × 10-3~Ω. cm2 and 0.31 eV of Schottky barrier height is achieved for a Ti/SF6-treated n-type Ge (n-Ge) ( Nd= 1 × 1017 cm-3) contact, exhibiting 1700 times ρc reduction from a Ti/nontreated n-Ge contact. A convenient and effective passivation process of the Ge surface is presented to alleviate Fermi-level pinning at metal/Ge contact and lower source/drain contact resistance of Ge n-type field-effect transistors.
Bibliographical notePublisher Copyright:
© 2015 IEEE.
- Fermi-level unpinning
- SF6 plasma
- contact resistance
- surface passivation
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering