Laser-cutting using selective polarization
AssigneeAsm Technology Singapore Pte Ltd
InventorsRuslan Rifovich SUBKHANGULOV, Paul Christiaan VERBURG, Denis Danisovich ARSLANOV, Roman Urs DOLL
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Abstract
A method of cutting a semiconductor wafer by selectively controlling and utilising the polarization of incident laser beam or beams that includes irradiating the semiconductor wafer with laser light having a first polarization state, and subsequently irradiating the semiconductor wafer with laser light having a second polarization state, the second polarization state being different from the first polarization state.
Claims11
A method of cutting a semiconductor wafer, comprising the steps of:
- a) providing a laser source for directing laser light to an irradiation region of a laser cutting apparatus,
- b) supporting the semiconductor wafer within the laser cutting apparatus such that the irradiation region is coincident with the semiconductor wafer, and
- c) irradiating the irradiation region of the semiconductor wafer with laser light having a first polarization state, and subsequently irradiating the irradiation region of the semiconductor wafer with laser light having a second polarization state, the second polarization state being different from the first polarization state.
10-18. (canceled)
Laser-cutting apparatus for cutting a semiconductor wafer, comprising:
- a laser source for emitting a laser beam;
- an optical guide system for receiving the laser beam and directing laser light to an irradiation region;
- a selectively actuatable optical polarizing component for switching a polarization state of the laser light directed to the irradiation region between a first polarization state and a second, different, polarization state;
- a support for supporting a semiconductor wafer in a position that is at least partially coincident with the irradiation region;
- and
- a drive for relatively moving the semiconductor wafer and the irradiation region such that the irradiation region follows a cut line of the wafer,
- wherein the selectively actuatable optical polarizing component comprises,
- 1) a quarter-wave plate selectively movable for changing elliptical or circular polarization of the laser beam, or
- 2) a plurality of half-wave plates, each being selectively movable for changing linear polarization of a respective output laser beam, or
- 3) a plurality of quarter-wave plates, each being selectively movable for changing elliptical or circular polarization of a respective output laser beam.
Dependencies are inferred from the claim text.