High crystalline quality erbium-doped zirconium oxide films were deposited on Si(100) by electron beam evaporation in high vacuum. Characteristics of light emission in the telecommunication window from erbium oxide crystal zirconium oxide films were investigated before and after furnace annealing in oxygen atmosphere. The luminescence intensity of the erbium-doped thin film after annealing at 900 °C was 18 times higher than those before thermal annealing. Also, it was observed a decrease in the intensity of luminescence and the 4 I 13/2 lifetime with the increase of the erbium concentration, which was analyzed via energy transfer -quenching. The structure environment of the erbium ion in the thin film before and after annealing has been studied by X-ray diffraction. The surface morphology of the films as a function of the annealing temperature and atmosphere showed a significant change.

Ti/Al ohmic contact with an extremely low specific contact resistance has been formed by the deposition of Ti and Al films on Si+ lanted GaN. The ohmic contact formed by annealing at 600 o C of Ti film with a thickness of 50 nm and Al film with a thickness of 200 nm reveals the good smooth surface and uniform structure as compare to those of contacts formed above 700 °C, which is correlated to whether the Al-Ti alloy is melted during the annealing of ohmic contact or not. The specific contact resistance of 2 × 10-6Ω-cm2 is obtained for Si+ implanted GaN with a dose of 5 × 1013 cm-2. As Si ion dose increases to 5 × 1014 /cm2, the specific contact resistance is reduced to 2 × 10-8 Ω-cm2. It is revealed that the selective doping at high impurity concentration in the surface region by Si+ implantation is useful to reduce the contact resistance for Ti/Al contact to GaN.