Apparatus and method for speckle reduction in laser processing equipment

摘要

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.

主权项

1. 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 one or more 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, wherein the refractive medium is a prism comprising a plurality of columns having a plurality of different lengths.