Fermi level depinning in Ti/n-type Ge Schottky junction by the insertion of fluorinated graphene.

The effect of fluorinated graphene (f-Gr) as the interfacial layer on Fermi level depinning in Ti/n-type Ge Schottky barrier diodes (SBDs) is intensively studied. Electrical properties of the SBDs are characterized by I-V method. The series resistance, barrier height and ideal factor of the SBDs are extracted by forward I-V, Cheung's method and Norde's method, respectively. Fluorinated graphene is found effective in reducing barrier height of Ti/Ge SBD. On the contrary, the SBD with graphene interlayer shows the increased barrier height and the barrier height changes significantly with bias voltage due to graphene induced Fermi level shift. Therefore, the fluorinated graphene is more stable and predictable in modifying metal/semiconductor interfaces, which can be further used in other metal/semiconductor contacts to achieve high quality SBDs. • Schottky barrier height lowering of Ti/n-type Ge SBD by insertion of fluorinated graphene. • Ti/graphene/n-type Ge SBD barrier height dependent on reverse bias voltage. • Ti/fluorinated graphene/n-type Ge SBD barrier height independent on reverse bias voltage. [ABSTRACT FROM AUTHOR]