The role of RF sputtering parameters on the uniformity and stability of Tb₄O₇ thin films on silicon substrates for passivation applications

Abstract In this study, the effects of different radio frequency (RF) parameters, were studied from the physical perspective of terbium oxide (Tb 4 O 7 ) thin films deposited on silicon (Si) substrates, emphasizing their uniformity and stability for passivation applications. The findings for sample C, indicate that an optimal sputtering power of 110 W for 40 min enhances film uniformity while minimizing surface roughness, which is critical for achieving a stable passivation film. Notably, all the studied samples revealed a crystalline nature and maintained a stable phase, with no impurities detected from the grazing incident x-ray diffraction (GIXRD) patterns. Sample C revealed the highest value of crystallite size measured at 38 nm. Additionally, band gap energy (Eg) values between 2.19 and 2.78 eV were measured using the Kubelka–Munk (K-M) method. Photoluminescence (PL) analysis showed sample C achieved the highest peak intensity at 548 nm, corresponding to the 5 D 4 → 7 F 5 transition. Studies have been conducted on the formation of Tb 4 O 7 thin films deposited by RF sputtering on Si substrates, annealed in an argon (Ar) atmosphere. This study introduces a new approach to enhancing film quality by adjusting the RF power during the sputtering process and subsequently annealing the sputtered samples. The aim was to investigate the benefits of nitrogen (N) annealing on the formation of a uniform passivation film of Tb 4 O 7 material.