Apparatus and method for speckle reduction in laser processing equipment
AssigneeApplied Materials, Inc.
InventorStephen MOFFATT
Life of this patent
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Abstract
Embodiments described herein provide apparatus and methods for processing semiconductor substrates with uniform laser energy. A laser pulse or beam is directed to a spatial homogenizer, which may be a plurality of lenses arranged along a plane perpendicular to the optical path of the laser energy, an example being a microlens array. The spatially uniformized energy produced by the spatial homogenizer is then directed to a refractive medium that has a plurality of thicknesses. Each thickness of the plurality of thicknesses is different from the other thicknesses by at least the coherence length of the laser energy.
Claims21
An apparatus for improving energy uniformity of coherent light, comprising:
- a plurality of lenses positioned to produce a composite projection field;
- and
- a refractive medium having one or more first surfaces and a plurality of second surfaces, wherein each second surface is located at a plurality of distances from the one or more first surfaces, and the refractive medium is positioned to receive the composite projection field at the one or more first surfaces and to transmit an energy field from the plurality of second surfaces, or the refractive medium is positioned to receive the composite projection field at the plurality of second surfaces and to transmit the energy field from the one or more first surfaces.
(canceled)
An apparatus for generating a uniform illumination field, comprising:
- a laser projecting radiation along an optical path;
- a plurality of lenses disposed along a plane perpendicular to the optical path;
- a refractive optic disposed along the optical path, the refractive optic having a first surface intersecting the optical path and a second surface intersecting the optical path, wherein the first surface defines a plane perpendicular to the optical path, and the second surface comprises a plurality of facets, each facet defining a plane perpendicular to the optical path, and wherein no two facets are the same distance from the first surface, the plurality of lenses being disposed between the laser and the refractive optic.
An apparatus for improving energy uniformity of coherent light, comprising:
- a plurality of lenses positioned to produce a composite projection field;
- and
- a refractive medium having a plurality of transit paths for the coherent light, the transit paths having a plurality of transit times through the refractive medium.
Dependencies are inferred from the claim text.