研究目的
To develop a technology for preparing amorphous nonstoichiometric hydrogenated silicon carbide (a-SixC1-x:H) films as antireflection and protective coatings for germanium in the IR spectral range, aiming to improve optical transmission and mechanical properties.
研究成果
The developed a-SixC1-x:H films effectively serve as antireflection and protective coatings for germanium in the IR range of 2.5–10 μm, significantly improving optical transmission (up to 96% for double-sided coatings) and providing good mechanical properties (hardness >12 GPa, Young's modulus ~100 GPa). The high deposition rate and tunable properties make these films promising for practical applications. Future work should focus on reducing absorption losses and optimizing for broader spectral ranges.
研究不足
The presence of Si-C bonds restricts the application range to the spectral interval 2.5–10 μm due to light absorption. Films cannot be used for wavelengths greater than 10 μm. Light absorption at C-H and Si-H bonds causes local minima in transmission spectra. Further optimization of deposition parameters is needed to reduce absorption and extend the spectral range.
1：Experimental Design and Method Selection:
The study uses plasma-enhanced chemical vapor deposition (PE-CVD) to deposit a-SixC1-x:H films. The rationale is to optimize film properties for antireflection coatings on germanium substrates. Theoretical models include the condition for optimal antireflection effect (n = √(n_substrate)) and optical modeling of transmission and reflection.
2：Sample Selection and Data Sources:
Substrates include boron-doped CZ Si (100), quartz plates, Al foils, and Ge wafers. Selection criteria involve suitability for IR optics and mechanical testing. Data acquisition is through ellipsometry, FTIR, UV-Vis-NIR spectrophotometry, and nanoindentation.
3：List of Experimental Equipment and Materials:
Equipment includes Sentech Depolab 200 PE-CVD system, Sentech LE400 laser ellipsometer, Shimadzu IRAffinity-1S FTIR setup, Agilent Cary 5000 UV-Vis-NIR spectrophotometer, and NanoIndenter G200 nano-hardness tester. Materials include gases (SiH4, CH4, H2, Ar), substrates (Si, quartz, Al, Ge), and chemicals for cleaning (distilled water, ethanol, HF solution).
4：Experimental Procedures and Operational Workflow:
Substrates are cleaned ultrasonically and with HF for Si. Plasma treatment with H2 is done to remove contaminants. Films are deposited at specified gas flow rates, pressure, temperature, and RF power. Post-deposition, samples are cooled naturally. Thickness, refractive index, and optical properties are measured using ellipsometry, FTIR, and spectrophotometry. Mechanical properties are assessed via nanoindentation with a Berkovich indenter.
5：Data Analysis Methods:
Data analysis involves calculating optical constants from ellipsometry, identifying bond types from FTIR spectra, determining optical bandgap using Tauc plots, and averaging hardness and Young's modulus from multiple nanoindentation tests.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
