Popis: |
We discuss the fabrication of GeO 2 and GeO 2 /SiO 2 films at room temperature by photo-chemical vapor deposition. Excimer lamps were used for the light source, and tetraethoxyorthogermanate (TEOG) and tetraethoxyorthosilicate (TEOS), as raw materials. First, we fabricated GeO 2 films from single-precursor TEOG. The surface of the films obtained with Ar 2 * , Kr 2 * , and Xe 2 * lamps was extremely smooth (R rms ∼0.3 nm). Second, we fabricated GeO 2 /SiO 2 composite films from a mixed vapor of TEOS and TEOG. In this instance, we used a Xe 2 * lamp, which was able to produce films of good quality for both SiO 2 and GeO 2 individually. The refractive indices of the obtained films showed intermediate values between those of SiO 2 (n =1.46) and GeO 2 (n =1.60). The relationship between the Ge concentration in these films and the refractive indices was examined. We successfully obtained a GeO 2 /SiO 2 composite material of higher refractive index than that of similar composites produced by conventional methods. |