Hydrazine-Based Fermi-Level Depinning Process on Metal/Germanium Schottky Junction

In this letter, we propose a hydrazine (N
₂
H
₄
)-based nitridation process, which reduces the native oxide (GeO
_x
) component and finally transforms it into GeO
_x
N
_y
on intrinsic Ge, to relieve the E
_F
pinning problem. The decomposition of GeO
_x
and formation of GeO
_x
N
_y
by N
₂
H
₄
are systematically investigated through cross-sectional transmission electron microscopy, X-ray photoelectron spectroscopy, and atomic force microscopy analyses. After performing the N
₂
H
₄
-based nitridation process for 12 h, high Φ
_H
(~0.59 eV) and therefore high ON/OFF current ratio (~10
⁴
) are achieved for Ti/Ge Schottky junction diode.