Patent ID: 7550236

Claim:
A mask for exposing a first layer and a second layer on a process substrate, where the first and second layers are two separate layers of an integrated circuit, the mask comprising: a mask substrate, where the mask substrate is substantially completely transmissive to a first wavelength of light and a second wavelength of light, a layer of a first material disposed on the mask substrate, where the first material is substantially opaque to the first wavelength of light and substantially transmissive to the second wavelength of light, and the layer of the first material is patterned for the first layer, and a layer of a second material disposed on the mask substrate, where the second material is substantially transmissive to the first wavelength of light and substantially opaque to the second wavelength of light, and the layer of the second material is patterned for the second layer, where the layer of the first material and the layer of the second material are aligned on the mask substrate for proper alignment of the first and second layers on the process substrate.