Deep ultra-violet light sources for wafer and reticle inspection systems
AssigneeKLA-Tencor Corporation
InventorsGang Lei, Damon F. Kvamme
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Abstract
Disclosed are methods and apparatus for generating a sub-208 nm laser. A laser apparatus includes one or more seed radiation sources for generating a first radiation beam having a first fundamental wavelength on a first optical path and a second radiation beam having a second fundamental wavelength on a second optical path, a first amplifier for amplifying the first radiation beam, a second amplifier for amplifying the second radiation beam, and a wavelength conversion module comprising a plurality of crystals for frequency multiplying and mixing the amplified first and second radiation beams to produce an output beam at a fifth harmonic that is less than about 208 nm.
Claims16
A laser apparatus for generating output radiation having a wavelength below about 208 nm, comprising:
- one or more seed radiation sources for generating a first radiation beam having a first fundamental wavelength on a first optical path and a second radiation beam having a second fundamental wavelength on a second optical path;
- a first amplifier for amplifying the first radiation beam;
- a second amplifier for amplifying the second radiation beam;
- and
- a wavelength conversion module comprising a plurality of crystals for frequency multiplying and mixing the amplified first and second radiation beams to produce an output beam at a fifth harmonic that is less than about 208 nm.
An inspection system for inspecting a photolithographic reticle or wafer for defects, comprising:
- a laser apparatus as recited in any of claims 1-8;
- imaging optics for directing the output beam towards a reticle or wafer;
- a detector for receiving a detected signal or image in response to the output beam being reflected from or transmitted through the reticle or in response to the output beam being reflected from the wafer;
- and
- a processor and memory that are configured to analyze the detected signal or image to thereby detect defects on the reticle or wafer.
A method of generating output radiation having a wavelength below about 208 nm, comprising:
- generating a first radiation beam having a first fundamental wavelength on a first optical path and a second radiation beam having a second fundamental wavelength on a second optical path;
- amplifying the first radiation beam;
- amplifying the second radiation beam;
- and
- frequency multiplying and mixing the amplified first and second radiation beams to produce an output beam at a fifth harmonic that is less than about 208 nm.
Dependencies are inferred from the claim text.