高周波スパッタ法によって作製されたAlPO₄-Al₂O₃系非晶質膜の物性と構造

抄録

Amorphous films in the system of AlPO₄-Al₂O₃ were prepared by rf sputtering, and their physical properties such as density, refractive index and thermal expansion coefficient, and the infrared absorption spectra were measured. The physical properties and the infrared absorption spectrum of an amorphous AlPO₄ were very similar to those of SiO₂ glass. All the physical properties of the amorphous AlPO₄-Al₂O₃ films had the same compositional dependence; that is, they increased linearly with increasing Al₂O₃ content up to about 80mol% Al₂O₃, beyond which they increased more rapidly. The results of infrared spectra indicated that the coordination number of aluminum ions was 4 below about 80mol% Al₂O₃ content, but increased rapidly to about 5 above 80mol% Al₂O₃, reaching to the value of an amorphous Al₂O₃ film.