Multi-spectral optical filter and method for fabricating the same

A method for fabricating a multi-spectral optical filter, the method

• comprising the following processes:
• providing a substrate;
• disposing a first reflection layer on the substrate;
• disposing a mask layer on the first reflection layer, wherein the mask layer exposes a first portion and a second portion an upper surface of the first reflection layer, respectively;
• disposing an inorganic layer on the mask layer;
• disposing a sacrificial layer on the inorganic layer;
• patterning the sacrificial layer to form a plurality of first sacrificial structures corresponding to the first portion and a plurality of second sacrificial structures corresponding to the second portion;
• reflowing the patterned sacrificial layer to form a stepped sacrificial layer, wherein the stepped sacrificial layer includes a first sacrificial film formed by the plurality of first sacrificial structures and a second sacrificial film formed by the plurality of second sacrificial structures;
• performing a pattern transferring process on the stepped sacrificial layer and the inorganic layer to form a stepped inorganic layer, wherein the stepped inorganic layer includes a first optical film corresponding to the first portion and a second optical film corresponding to the second portion;
• and
• disposing a second reflection layer on the stepped inorganic layer.