霍尔离子源辅助制备长波红外碳化锗增透膜

为了提高锗基底的透过率和环境适应性,镀制了增透保护膜。应用电子枪蒸发加霍尔离子源辅助的方法沉积了碳化锗(Ge_1-xC_x)薄膜。通过固定霍尔离子源参数,控制沉积速率的工艺得到了不同光学常数的碳化锗薄膜。X射线衍射(XRD)测试表明,所制备的碳化锗薄膜在不同的沉积速率下均为无定形结构。采用傅立叶变换红外(FTIR)光谱仪测量了试片的透过率,使用包络法获得了相应工艺条件下的光学常数。在锗基底上双面镀制碳化锗增透膜后,长波红外7.5～11.5 μm波段的平均透过率T_ave>85%。经过环境实验之后的碳化锗膜层完好,证明碳化锗增透膜具有良好的环境适应性。

Fabrication of The Long-wave Infrared Germanium Carbide Antireflection Coatings by End-Hall Ion Source

The antireflective and protective coatings were deposited on the germanium substrates to improve the transmittance and the environmental adaptability. The germanium carbide (Ge_1-xC_x) coatings were successfully fabricated.The pure germanium was evaporated by the e-gun, and the methane was directly ionized by End-Hall ion source.The different optical constants of the germanium carbide coatings were obtained by controlling the deposition rate and fixing End-Hall ion source parameters. The germanium carbide coatings with different deposition rates were all amorphous tested by X-ray diffraction. The optical constants were calculated by the envelope method from the transmittance data measured by Fourier transform infrared (FTIR) spectrometer. After double-side depositing the germanium carbide coatings on the germanium substrate, an average transmittance T_ave>85% was achieved in the long-wave infrared region of 7.5～11.5 μm. After the environment tests, the germanium carbide coating was fine, this indicates the germanium carbide coating has great environmental adaptability.