Improvement in a vacuum ultraviolet ellipsometer for measuring absolute complex dielectric constants of anisotropic III-V nitride semiconductors

LED和光电二极管等半导体器件不仅在可见光领域，而且在紫外区都有很好的应用前景。然而，对这些半导体材料的光学性质的研究需要包括真空紫外线(VUV)在内的宽波长区域。然后，我们的最终目标是永久安装一台非常独特的具有同步辐射的真空紫外椭偏仪，以测量这些半导体材料从可见光到真空紫外的绝对复折射率，因为同步辐射是理想的紫外线光源。然后，我们一直在建造一台同步加速器专用椭偏仪，并将在下一次机器时间进行全面的运行测试。

Semiconductor devices such as LED and photodiode are promising ones for not only visible but also ultraviolet region. However, investigations into the optical properties of these semiconductor materials require wide wavelength region including vacuum ultraviolet (VUV). Then, our final target is the permanent installation of a very unique VUV ellipsometer with the synchrotron radiation to measure absolute complex refractive indices of those semiconductor materials from visible to VUV, because synchrotron radiation is the ideal ultraviolet light source. Then, we have been constructing a synchrotron dedicated ellipsometer and over-all operation testing will be carried out at the next machine time.