摘要 |
A method of fabricating a phase shifting reticle that can be used as a mask in photolithographic processes such as semiconductor wafer patterning. A transparent quartz substrate is coated with a film of an oxidizable silicon material. The silicon is then coated with a material suitable for isolating the silicon material from an oxidizing environment. A resist coating is placed atop the isolation material, developed and etched, exposing the isolation in a predetermined pattern. The isolation material is etched and the substrate placed in an oxidizing environment. The silicon material expands to a predetermined thickness, forming a phase shifter on the substrate. Next, the remaining isolation material and unoxidized silicon are removed, forming transmission regions adjacent the phase shifters. Then the remaining resist is removed to form opaque or light blocking areas on the substrate to complete formation of a phase shifting reticle.
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