Enhanced Remnant Polarization (30 μC/cm2) and Retention of Ferroelectric Hf0.5Zr0.5O2 by NH3 Plasma Treatment

In this letter, NH
₃
plasma treatment was utilized to improve the ferroelectric property of widely used TiN/Hf
_x
Zr
_y
O
₂
(HZO)/TiN capacitors. The developed metal-ferroelectric-metal (MFM) structure shows high remnant polarization (P
_r
) of
$30 ~\mu \text{C}$
/cm
²
after 10-min NH
₃
treatment at bottom TiN electrode. Materials characterization were subject to investigate the behind mechanism. A higher ferroelectric o-phase formation in NH
₃
-treated HZO device is revealed by grazing incidence X-ray diffraction (GIXRD). In addition, the high-resolution transmission electron microscopy (HRTEM) indicates that the NH
₃
treatment optimizes the interface quality by restraining of the interfacial layer (IL) including intrinsic TiO
_x
N
_y
dead-layer and non-ferroelectric layer. Furthermore, the improved interface engineering also suppressed the imprint effect, which prompts the retention improvement of TiN/Hf
_x
Zr
_y
O
₂
/TiN ferroelectric capacitors.