氧气/氩气流量比对柔性和刚性衬底上的非晶Ga2O3薄膜性能的影响

Effect of Oxygen/Ar Flow Rate Ratio on Properties of Amorphous Ga2O3 Thin Films on Flexible and Rigid Substrates

摘要:

利用射频磁控溅射沉积技术在柔性聚酰亚胺、刚性石英玻璃和硅片衬底上于室温条件下制备了非晶Ga₂O₃薄膜，研究并阐明了氧气/氩气流量比对非晶Ga₂O₃薄膜的结构、光学、表面形貌及化学键结构特性的影响规律。结果表明，非晶Ga₂O₃薄膜在300~2000 nm波长范围内的平均光学透过率大于80%。当非晶Ga₂O₃薄膜生长过程中氧气/氩气流量比从0升高到0.25时，由于薄膜中氧空位缺陷浓度降低，非晶Ga₂O₃薄膜的光学带宽从4.97 eV增加到5.13 eV；非晶Ga₂O₃薄膜的光学折射率和表面粗糙度均随着氧气/氩气流量比达到0.25时最优。同时，X射线光电子能谱测试结果表明，随着氧气/氩气流量比从0升高到0.25，非晶Ga₂O₃薄膜O 1s峰中氧空位和氧-镓化学键的比例逐渐降低，从而证实了升高薄膜生长过程中的氧气/氩气流量比，能够降低非晶Ga₂O₃薄膜中的氧空位缺陷浓度，以获得最优化的非晶Ga₂O₃薄膜性能，为实现高性能的柔性和刚性基于非晶Ga₂O₃薄膜的日盲深紫外探测器件奠定研究基础。

Abstract:

Amorphous Ga₂O₃ (a-Ga₂O₃) thin films were prepared on flexible polyimide, rigid quartz glass, and Si substrates via radio frequency magnetron sputtering at room temperature. The effect of oxygen/Ar flow rate ratio on the structure, optical property, surface morphology, and chemical bonding properties of the a-Ga₂O₃ films was investigated. Results show that the average optical transmittance of the a-Ga₂O₃ films is over 80% within the wavelength range of 300–2000 nm. The extracted optical band gap of the a-Ga₂O₃ films is increased from 4.97 eV to 5.13 eV with the increase in O₂/Ar flow rate ratio from 0 to 0.25, due to the decrease in concentration of oxygen vacancy defects in the film. Furthermore, the optical refractive index and surface roughness of the a-Ga₂O₃ films are optimized when the O₂/Ar flow rate ratio reaches 0.25. X-ray photoelectron spectroscopy analysis also shows that the proportion of oxygen vacancies (V_O) and Ga-O chemical bonds in the O 1s peak is gradually decreased with the increase in O₂/Ar flow rate ratio from 0 to 0.25, proving that increasing the O₂/Ar flow rate ratio during film growth can reduce the concentration of oxygen vacancy defects in a-Ga₂O₃ films. In this case, a-Ga₂O₃ with optimal properties can be obtained. This work provides a research basis for high-performance flexible and rigid deep ultraviolet solar-blind detection devices based on a-Ga₂O₃ films.