s
High-
k
metal oxide films are vital for the future development of microelectronics technology. In this work, ZrO
2
films were grown on silicon by atomic layer deposition (ALD) using tetrakis(dimethylamido)zirconium and ozone as precursors. The relatively constant deposition rate of 0.125 nm/cycle is obtained within the ALD temperature window of 200–250 °C. The film thickness can be precisely controlled by regulating the number of ALD cycle. The ZrO
2
films formed at 200–250 °C have an O/Zr atomic ratio of 1.85–1.9 and a low content of carbon impurity. ZrO
2
film begins to crystallize in ALD process above 210 °C, and the crystal structure is changed from cubic and orthorhombic phases to monoclinic and orthorhombic phases with increasing the deposition temperature to 350 °C. Moreover, the effect of annealing temperature on dielectric properties of ZrO
2
film was studied utilizing ZrO
2
-based MIS device. The growth of the interface layer between ZrO
2
and Si substrate leads to the decrease in the capacitance and the leakage current of dielectric layer in the MIS device after 1000 °C annealing. ZrO
2
film exhibits the relatively high dielectric constant of 32.57 at 100 kHz and the low leakage current density of 3.3 × 10
−6
A cm
−2
at 1 MV/cm.
s
Nanolayered Ta
2
O
5
-Al
2
O
3
composite films were grown on
n
-type silicon by atomic layer deposition (ALD) within the overlapped ALD window of 220–270 °C. Moreover, post-annealing treatment was carried out to eliminate defects and improve film quality. Nanolayered Ta
2
O
5
-Al
2
O
3
composite films remain amorphous after 700 °C annealing. The effects of composition, interface, and deposition sequence on electrical properties of Ta
2
O
5
-Al
2
O
3
composite films were investigated in detail utilizing MIS devices. The results demonstrate that the formation of Ta
2
O
5
-Al
2
O
3
composite films by mixing Al
2
O
3
into Ta
2
O
5
can decrease the leakage current effectively, but it leads to the decrease of the dielectric constant and the enhancement of the hysteresis effect. The interfaces in composite films are not conducive to prevent the leakage current. The deposition sequence of Si/(Al
2
O
3
/Ta
2
O
5
)
n
, Al
2
O
3
as the first covering layer, reduces the leakage current and the hysteresis effect effectively. Therefore, the electrical properties of Ta
2
O
5
-Al
2
O
3
composite films could be regulated by adjusting components and structures via ALD to acquire relatively great dielectric constants and acceptable leakage currents.
CeO2 nanospheres with different diameters were successfully prepared and embedded in one-dimensional chitosan/polyvinyl alcohol (CS/PVA) composite nanofibers by electrospinning technique for further antibacterial evaluation. The obtained composites exhibited different antibacterial activities to Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli). We propose that CeO2-CS/PVA nanofibrous membranes with attractive antibacterial activities witness the practical use for tissue engineering such as wound dressing.
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