Abstract
Yttrium oxide (Y
2O
3) thin films were grown at substrate temperatures (T
s) ranging from room temperature (RT) to 500
°C and their structural and electrical properties were evaluated. The results indicate that Y
2O
3 films grown at RT-100
°C were amorphous (a-Y
2O
3). Y
2O
3 films began to show cubic phase (c-Y
2O
3) at T
s
=
200
°C. The average grain size varies from 5 to 40
nm as a function of T
s. Room temperature ac electrical conductivity increases from 0.4 (Ω-m)
−
1
to 1.2 (Ω-m)
−
1
with increasing T
s from RT to 500
°C. The frequency dispersion of the electrical resistivity reveals the hopping conduction mechanism. Frequency dispersion of the electrical resistivity fits to the modified Debye's function, which considers more than one ion contributing to the relaxation process. The mean relaxation time decreases from 2.8 to 1.4
μs with increasing T
s indicating that the effect of microstructure of the Y
2O
3 films is significant on the electrical properties.