Paper TF+AS+SS-ThA9
Growth, Microstructure and Optical Properties of Sputter-Deposited Gallium Oxide Thin Films

Thursday, November 1, 2012, 4:40 pm, Room 11

Gallium oxide (β-Ga₂O₃), which is a stable oxide of gallium, is a wide band gap material. The high melting point coupled with stable structure makes of β-Ga₂O₃ the best candidate for high temperature sensing. β-Ga₂O₃ thin films can be used for developing oxygen sensors operating at higher temperatures (≥ 900 ^oC). This feature opens the possibility of developing the integrated of β-Ga₂O₃ based oxygen sensors for power generation systems. The present work was performed on the analysis of growth behavior, microstructure, and optical properties of of β-Ga₂O₃ films grown by sputter deposition. Ga₂O₃ thin film were deposited on Si(100) and quartz substrate by varying the growth temperature from room temperature to 800 ^oC. The characteristic analysis of the samples was performed employing grazing incidence X-ray diffraction (GIXRD), scanning electron microscopy (SEM), and spectrophotometry measurements. GIXRD analyses indicate that the samples grown at lower temperatures were amorphous while those grown at ≥ 400 ^oC. SEM results indicate that the morphology evolution is dependent on the temperature. The characteristic shape of the grains changed from triangular to square and finally to spherical morphology with increasing temperature. Optical characterization indicates that the band gap varies from 4.1 to 5.1 eV as a function of increasing temperature. The correlation between growth conditions, microstructure and band gap is established.