Systems and methods for a narrow band high transmittance interference filter

A method for fabricating a semiconductor device, the method comprising:

• providing a wafer for a lithography system, wherein the lithography system includes an interference filter that includes:
• a transparent substrate having a first surface and a second surface,
• a first material layer stack having an odd number of alternating amorphous material layers formed over the first surface of the transparent substrate, wherein:
• a sequence of the amorphous material layers alternates between a first refractive index and a second refractive index;
• the amorphous material layers include a first amorphous material layer that physically contacts the first surface of the transparent substrate, a second amorphous material layer over the first amorphous material layer, and a fifth amorphous material layer further away from the first surface of the transparent substrate than any other material layers of the first material layer stack, wherein the first amorphous material layer and the fifth amorphous material layer have a same thickness measured in a direction perpendicular to the first surface of the transparent substrate;
• and
• the first amorphous material layer has the first refractive index, the second amorphous material layer has the second refractive index, and the first refractive index is higher than the second refractive index, and
• a second material layer stack having an even number of alternating material layers formed over the second surface of the transparent substrate;
• and
• performing a patterning process on the wafer with the lithography system.

A method for fabricating a semiconductor device, the method comprising:

• providing a wafer that is to undergo one or more processing steps;
• forming a photoresist layer on the wafer;
• providing the wafer to a lithography system, the lithography system having an interference filter that includes:
• a transparent substrate having a first surface and a second surface,
• a first plurality of an odd number of alternating material layers formed over the first surface of the transparent substrate, the first plurality of the odd number of the alternating material layers comprising:
• a first amorphous material layer that physically contacts the first surface of the transparent substrate;
• a second amorphous material layer, wherein the first amorphous material layer has a higher refractive index than the second amorphous material layer;
• and
• a fifth amorphous material layer further away from the first surface of the transparent substrate than any other material layers of the first plurality of the odd number of the alternating material layers, wherein the first amorphous material layer and the fifth amorphous material layer have a same thickness measured in a direction perpendicular to the first surface of the transparent substrate, and
• a second plurality of an odd number of alternating material layers formed over the second surface of the transparent substrate, the second plurality of the odd number of the alternating material layers comprising:
• a third amorphous material layer that physically contacts the second surface of the transparent substrate, the third amorphous material layer having the same refractive index as the second amorphous material layer;
• a fourth amorphous material layer disposed over the third amorphous material layer, wherein the third amorphous material layer has a lower refractive index than the fourth amorphous material layer;
• and
• a sixth amorphous material layer positioned further away from the second surface of the transparent substrate than any other material layers of the second plurality of the odd number of the alternating material layers, the first amorphous material layer having the same refractive index as the fourth, fifth, and sixth amorphous material layers, and
• performing a patterning process on the wafer.