Exposure apparatus employing a photomask
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorKazuya Kamon
Life of this patent
Estimating the term…
Abstract
A reflection photomask includes a substrate and first and second reflection circuit patterns on the substrate so that light reflected from the first reflection circuit pattern has a different phase from light reflected from the second reflection circuit pattern. Interference between the reflected light bundles produces dark, i.e., non-illuminated, regions. An exposure apparatus includes a light source, a Koehler illumination optical system for irradiating a reflection photomask including a circuit pattern with light emitted from the light source, and a projection optical system for converging the light reflected from the reflection photomask onto a substrate to project the circuit pattern onto the substrate.
Claims2
An exposure apparatus comprising:
- a light source for emitting light;
- a Koehler illumination optical system for irradiating a reflection photomask including a circuit pattern with light emitted from said light source, said Koehler illumination optical system including a fly-eye lens for dividing light emitted from said light source into a plurality of light bundles, a half mirror for reflecting the plurality of light bundles produced by said fly-eye lens, and a lens for irradiating the reflection photomask with the plurality of light bundles reflected from said half mirror;
- and
- a projection optical system for converging the light reflected from the reflection photomask onto a substrate to project the circuit pattern of the reflection photomask onto the substrate.
Dependencies are inferred from the claim text.