On the physical properties of In2O3 films prepared by atomic layer deposition using tri-methyl-indium and nitrous oxide

Indium oxide (In
2
O
3
) films were directly grown on (0001)-plane sapphire substrates by atomic layer deposition (ALD) using tri-methyl-indium (TMIn) and nitrous oxide (N
2
O). The structural, optical and transport properties of the In
2
O
3
films were characterized by θ-to-2θ x-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM), Hall measurements, and transmission spectroscopy. Based on the XRD results, In
2
O
3
films were found to show ≪111≫ preferred orientation. As-grown In
2
O
3
films are n-type in nature with typical room temperature (RT) electron concentrations and mobilities being in low 10
¹⁸
cm
⁻³
and 10∼20 cm
²
/V-sec, and the optical transmittances and resistivities of the In
2
O
3
films are typically ∼80% and low 10
⁻¹
Ω-cm, respectively.