Analysis of electrical properties in MOS structure with a low surface roughness Al2O3-doped ZnO film as gate oxide

This experiment, liquid phase deposition (LPD) was used to deposit a Zinc Oxide thin film and doped with Al
2
O
3
as a dielectric layer on a P-type silicon substrate to fabricate a metal-oxide-semiconductor (MOS) capacitor. Discuss the effect of doping different volumes of Al
2
O
3
(0, 1, 3, 5 ml) on the electrical properties of the film. Appropriate doping of Al
2
O
3
can reduce the surface roughness of the film. According to the experimental data, it has better electrical properties when doped with 3 ml of Al
2
O
3
and vacuum annealed at 700°C for 1 hour. According to the experimental results, oxide layer charge, dielectric constant, equivalent oxide thickness (EOT), density of interface traps (D
it
), leakage current density and average roughness are 213.3 pF, 65.3, 11.45 nm, 4.25 × 10
¹¹
cm
^-2
eV
^-1
, 3.18 × 10-5 A/cm2 at +5 V and 1.59 nm. A higher k value can effectively reduce the direct tunneling leakage current under the trend of smaller and smaller components in the future.