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US 5,315,349 AGranted
Projection aligner
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorKazuya Kamon
Life of this patent
Estimating the term…
Abstract
A projection aligner includes a light source for emitting light, a mask including a focusing pattern and a condensing lens for condensing the light on the mask. Light-intercepting members and light-transmitting portions are alternatingly arranged in the focusing pattern. The projecting aligner includes a projecting lens for condensing the light on a surface of a wafer and a sensor for measuring the amount of the light transmitted through the focusing pattern after the light has passed through the focusing pattern on the mask and been reflected from the surface of the wafer.
Claims4
A projection aligner comprising:
- a light source for emitting exposure light for exposing a photosensitive surface of a wafer;
- a mask including a focusing pattern having light-blocking members and light-transmitting portions alternatingly arranged;
- a condensing lens for condensing the exposure light onto said mask;
- a converging lens for condensing the exposure light passing through the mask including the focusing pattern to illuminate the photosensitive surface of the wafer and for transmitting the exposure light reflected from the photosensitive surface of the wafer to the mask including the focusing pattern;
- a half-mirror for reflecting exposure light transmitted through the light-transmitting portions of the focusing pattern of the mask after reflection from the photosensitive surface of the wafer, said half-mirror being disposed between said condensing lens and said mask;
- and
- a sensor for measuring the amount of the exposure light reflected from said half-mirror.
4 more elements
Dependencies are inferred from the claim text.