【摘要】 利用引进的6 kW微波等离子体化学气相沉积设备,进行了无支撑金刚石膜工艺的初步研究。在800~1050℃的基片温度范围内,金刚石膜都呈(111)择优取向;基片相对位置对沉积较大面积、光学级金刚石膜至关重要。制出0.25 mm厚Φ50 mm的无支撑金刚石膜。拉曼光谱和X射线衍射分析表明,合成的金刚石膜晶体结构完整,sp2含量极低;透过率测试结果说明了优良的光学性能:截止波长225 nm,光学透过率(λ≥2.5μm)≥70%。更多还原

【Abstract】 The high quality free-standing diamond films were grown by 6kw microwave plasma chemical deposition(MPCVD) on n-type Si(100) wafer substrates.The impacts of the growth conditions,including the substrate temperature and position,pressure,ratio of CH4/H2 flow rates,and microwave power,on microstructures and properties of the diamond films were characterized with X-ray diffraction(XRD),scanning electron microscopy(SEM),Raman spectroscopy,and conventional probes.The results show that the temperature and position of the substrate significantly affect the film growth,and that few sp2 exists.For instance,at a temperature in the range from 800℃ to 1050℃,the grain in the compact diamond films grows preferentially in(111).The substrate position plays an important role in growth of large area,uniform,optical diamond films.Under the optimized conditions,the free-standing diamond films,with a thickness of 0.25 mm,a diameter of 50 mm,a cutoff frequency of 225 nm,and a transmittance(λ≥2.5 μm) greater than 70%,were obtained.更多还原