高功率MPCVD金刚石膜透波窗口材料制备研究

使用自行研制的椭球谐振腔式MPCVD装置,以H2-CH4为气源,在沉积功率8 kW条件下,对大面积金刚石膜透波窗口材料进行了制备研究.分别使用扫描电镜、Raman、分光光谱仪、热导率测试仪和空腔谐振法对金刚石膜的表面形貌、品质、光透过率、热导率和微波复介电常数等进行了表征及测试.实验结果表明,使用自行研制的椭球谐振腔式MPCVD装置,能够满足较高功率下高品质金刚石膜的快速沉积；抛光后的自支撑金刚石膜具有高的光学透过率和热导率,在23 ～ 36 GHz频率范围内微波介电损耗小于1×10-4,有着良好的微波介电性能,是较为理想的透波窗口材料.

Synthesis of Diamond Film as Electromagnetic Window Material by an Ellipsoidal MPCVD Reactor at High Input Microwave Power Levels

Polycrystalline diamond film was grown using H2-CH4 as the source gas in a newly developed ellipsoidal MPCVD reactor at 8 kW microwave power levels.Surface morphology,quality,transmittance,thermal conductivity as well as complex permittivity of the diamond film were examined by scanning electron microscopy,Raman spectroscopy,spectrophotometer,thermal constant tester and cavity resonator method respectively.The result proved that the new ellipsoidal microwave plasma CVD reactor has the ability to deposit high quality diamond films at a high synthesis rate.After polished on both sides,the free-standing diamond film has high transmittance and thermal conductivity.At the same time the film has excellent microwave dielectric properties for complex permittivity less than 1×10-4 in the range of 23-36 GHz,this show the film is one of the perfect electromagnetic window materials.