PURPOSE: To almost avoid infiltration of water content to a metallic reflecting layer, to prevent corrosion of the metallic reflecting layer and to prevent the deterioration in the reflectance by covering the surface of the metallic reflecting layer with a protection layer made of an inorganic group material.
CONSTITUTION: A metallic reflecting layer 21 is formed on a base 20 and a protection layer 22 made of an inorganic group material is provided on the surface of the metallic reflecting layer 21. The close adhesion between the metallic reflecting layer 21 and the protection layer 22 is improved by coating the surface of the metallic reflecting layer 21 with the protection layer 22 made of an inorganic group material in this way, the invasion of water content onto the metallic reflecting layer 21 is hardly caused, and corrosion of the metallic reflecting layer 21 is prevented. Moreover, a binary target is used to adjust the concentration of a metallic material thereby implementing consecutive sputtering and film forming is attained at a low cost.
NUMATA TAKEHIKO
NAITO KAZUNORI
