| 摘要 |
PURPOSE:To enable to form a thin film having sufficient adhesion on both the edge faces of a semiconductor element, and to facilitate formation of the thin film thereof by a method wherein the thin film consisting of elements of two kinds or more, and varying the composition ratio in the thickness direction of the film is adhered to the edge face of a cavity. CONSTITUTION:Relation between the (y) value and refractivity of AlOy is as shown in the figure (b), moreover Al2O3 has refractivity of 1.69-1.78, and alphaAlO has 1.13. by forming Al2O3 and AlO alternately, a multilayer film having high refractivity films and low refractivity films can be formed as shown in the figure (a). When formation of the film is to be performed by high-frequency (RF) sputtering, a target of Al2O3 is used, and after the inside of a bell jar is made to reach a superiorly high vacuum, sputtering is performed introducing gas of Ar, etc. In this condition, Al2O3 is sputtered in the shape of the still lower class oxide. When oxygen is introduced in the bell jar, the mol fraction of oxygen in the thin film is elevated. When the layers having high refractivity and low refractivity are desired to be formed alternately, it can be attained by performing alternately operations to increase and decrease abruptly the oxygen quantity to be introduced for the prescribed film thickness growing hours. |
