Characteristics of atomic layer deposition-derived all-high-k-based structures for flash memory application

A charge trapping flash memory using amorphous Al
₂
O
₃
as the tunneling layer, La-doped HfO
₂
films as the charge trapping layer and pure HfO
₂
as the blocking layer was fabricated and investigated. X-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), and transmission electron microscopic (TEM) were used to characterize the structures and microstructures. The HfO
₂
/ (HfO
₂
)
_0.75
(La
₂
O
₃
)
_0.25
(HLO) /Al
₂
O
₃
/Si stack annealed at 800°C shows distinct interface and nanocrystals in charge trapping layer. The electrical characteristics and charge storage properties of the HfO
₂
/ HLO/Al
₂
O
₃
/Si stack were also evaluated. The HfO
₂
/ HLO/Al
₂
O
₃
/Si stack annealed at 800°C exhibits a large memory window (9V at ±11 V, 1 s).