PURPOSE: To obtain a filter good in color reproductivity also with good reproductivity in manufacturing a color separation filter using a semiconductor filter, by lowering the temp. of a base to a specified temp. or less in the following step of the heat treatment in an atmosphere contg. halogen ions or a gas.
CONSTITUTION: Stripes of cyan multilayer interference films 42 are formed on a glass base 41, and onto these filters an Al2O3 film 43 as an optical adjustment layer and a ZrO2 layer 44 as the first reflection preventive layer are vapor deposited. Further, a Zn0.2Cd0.8S film 45 is formed and this base 33 is placed into a heat treatment pipe 31, and heat-treated at 400°C for about 30min by using an electric furnace 32, introducing gaseous Ar contg. CCl4. Superior spectral characteristics are obtained by this treatment. Then, a ZrO2 film 46 is vapor deposited at the second reflection preventive layer at room temp. W400°C, and when needed, a glass film 47 is vapor deposited at 150W300°C to smooth the filter. After the treatment with CCl4 the necessary treatment steps are carried out up to 400°C without deteriorating spectral characteristics, and its yield is raised.
AOKI YOSHITAKA
FUJIWARA SHINJI
