Tailoring oxygen vacancies in Ga2O3 thin films and controlled formation of Ga2O3/SiO2 heterostructures via annealing

IF 3.8 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Vacuum Pub Date : 2024-10-31 DOI:10.1016/j.vacuum.2024.113791

Asma O. Al Ghaithi , Inas Taha , Sumayya M. Ansari , Nitul Rajput , Baker Mohammad , Haila M. Aldosari

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引用次数: 0

Abstract

This study examines the effects of annealing duration on the oxygen vacancies in gallium oxide (Ga₂O₃) thin films. Ga₂O₃ thin films were deposited by RF magnetron sputtering on (100) silicon substrates and subsequently annealed in an argon atmosphere at 1000 °C for 1, 2, 4, and 7 h. The impact of the annealing time on the morphology, oxygen content, optical bandgap, and thickness of Ga₂O₃ thin films was thoroughly investigated. All annealed films exhibited a polycrystalline β-Ga₂O₃ phase with a monoclinic crystal structure and a preferred orientation along the (400) plane. Increasing the annealing time resulted in larger grains, a denser interfacial layer, and reduced microstrain. Prolonged annealing also facilitated the escape of oxygen atoms, creating oxygen vacancies that formed a defect band below the conduction band, significantly lowering the optical bandgap. Cross-sectional transmission electron microscopy revealed a Ga₂O₃/SiO₂ heterostructure formation, with Ga₂O₃ thickness decreasing and SiO₂ thickness increasing with longer annealing times. These findings enhance the understanding of the role of annealing in optimizing Ga₂O₃ thin films for electronic and optoelectronic applications.

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调整 Ga2O3 薄膜中的氧空位并通过退火控制 Ga2O3/SiO2 异质结构的形成

本研究探讨了退火时间对氧化镓（Ga2O3）薄膜中氧空位的影响。研究人员采用射频磁控溅射法在 (100) 硅基底上沉积 Ga2O3 薄膜，然后在 1000 °C 的氩气环境中分别退火 1、2、4 和 7 小时。所有退火薄膜都呈现出多晶β-Ga2O3相，具有单斜晶体结构，并沿(400)面优先取向。延长退火时间可使晶粒增大，界面层更致密，并降低微应变。延长退火时间还有利于氧原子逸出，产生氧空位，形成低于导带的缺陷带，显著降低了光带隙。横截面透射电子显微镜显示了 Ga2O3/SiO2 异质结构的形成，随着退火时间的延长，Ga2O3 厚度减小，SiO2 厚度增加。这些发现加深了人们对退火在优化 Ga2O3 薄膜在电子和光电应用中的作用的理解。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Vacuum 工程技术-材料科学：综合

CiteScore

6.80

自引率

17.50%

发文量

审稿时长

34 days

期刊介绍： Vacuum is an international rapid publications journal with a focus on short communication. All papers are peer-reviewed, with the review process for short communication geared towards very fast turnaround times. The journal also published full research papers, thematic issues and selected papers from leading conferences. A report in Vacuum should represent a major advance in an area that involves a controlled environment at pressures of one atmosphere or below. The scope of the journal includes: 1. Vacuum; original developments in vacuum pumping and instrumentation, vacuum measurement, vacuum gas dynamics, gas-surface interactions, surface treatment for UHV applications and low outgassing, vacuum melting, sintering, and vacuum metrology. Technology and solutions for large-scale facilities (e.g., particle accelerators and fusion devices). New instrumentation ( e.g., detectors and electron microscopes). 2. Plasma science; advances in PVD, CVD, plasma-assisted CVD, ion sources, deposition processes and analysis. 3. Surface science; surface engineering, surface chemistry, surface analysis, crystal growth, ion-surface interactions and etching, nanometer-scale processing, surface modification. 4. Materials science; novel functional or structural materials. Metals, ceramics, and polymers. Experiments, simulations, and modelling for understanding structure-property relationships. Thin films and coatings. Nanostructures and ion implantation.