Solid-state laser system for ultra-violet micro-lithography
AssigneeJMAR Technology Co.
InventorHenry Shields
Life of this patent
Estimating the term…
Abstract
A solid state laser systems for generating highly monochromatic laser radiation at wavelengths of interest for advanced micro-lithography, particularly 248 nanometer and 193 nanometer wavelengths. At least one Nd:YAG laser produces a 1,064 nm laser beam consisting of narrow-linewidth pulses of infra-red laser radiation having a pulse duration of less than 30 nanoseconds, at a pulse rate preferably in excess of 500 pulses per second with pulse energy greater than 20 millijoules. This radiation is frequency doubled and frequency tripled to produce 532 nm and 355 nm pulsed laser beams. These beams are then further optically processed to generate the ultra-violet wavelength for micro-lithography at either 248 nm or 193 nm.
Claims51
A system for generating substantially monochromatic ultraviolet laser radiation at a wavelength of approximately 193 nm, comprising:
- A) a Nd:YAG laser producing a primary laser beam comprising pulses of laser radiation at a wavelength of approximately 1064 nm,
- B) at least one first frequency multiplication crystal shaped and arranged to generate radiation at a wavelength of approximately 532 nm from said approximately 1064 nm laser radiation,
- C) at least one second frequency multiplication crystal shaped and arranged to generate radiation at a wavelength of approximately 355 nm utilizing said approximately 1064 nm laser radiation, and
- D) optical processing system receiving said radiation generated by said first frequency multiplication crystal and said radiation generated by said second frequency multiplication crystal and outputting an output beam having radiation at a wavelength of approximately 193 nm.
A system for generating with a Nd:YAG laser highly monochromatic ultraviolet laser radiation, comprising:
- A) at least one Nd:YAG laser producing a primary laser beam comprising narrow-linewidth pulses of p polarized infra-red laser pulses of radiation at a wavelength of approximately 1064 nm,
- B) a type I LBO crystal shaped and arranged to double the frequency of a portion of said 1064 nm beam to produce a first combined beam comprising p polarized radiation at 1064 nm and s polarized 532 nm radiation,
- C) a type II LBO crystal shaped and arranged to convert said combined beam to a second combined beam comprising p polarized radiation at 1064 nm, s polarized nm radiation and p polarized 355 nm radiation, and
- D) optical processing system receiving said radiation generated by said type I LBO crystal and said radiation generated by said type II LBO crystal and generating a an output beam with a wavelength of approximately 193 nm.
A system for generating with a Nd:YAG laser substantially monochromatic ultraviolet laser radiation comprising:
- A) a laser source producing a primary laser beam comprising pulses of laser radiation at a wavelength of approximately 1064 nm,
- B) a first crystal shaped and arranged to double the frequency of a portion of said 1064 nm beam to produce a first combined beam comprising radiation at 1064 nm and 532 nm,
- C) a second crystal shaped and arranged to convert said first combined beam to a second combined beam comprising radiation at 1064 nm, 532 nm and 355 nm, and
- D) optical processing system receiving said second combined beam and outputting and output beam having a wavelength suitable for generating patterns on a semiconductor waver substrate.
A system for generating substantially monochromatic ultraviolet laser radiation at a wavelength of approximate 193 nm, comprising:
- a first laser source providing a first primary laser beam comprising pulses of laser radiation at a wavelength of approximately 1064 nm;
- at least one first frequency multiplication crystal shaped and arranged to generate radiation at a wavelength of approximately 532 nm from said approximately 1064 nm laser radiation in said first primary laser beam;
- a second laser source providing a second primary laser beam comprising pulses of laser radiation at a wavelength of approximately 1064 nm;
- at least one second frequency multiplication crystal shaped and arranged to generate radiation at a wavelength of approximately 355 nm from said approximately 1064 nm laser radiation in said one of the first or the second primary laser beam;
- and
- optical processing system receiving said radiation generated by said first frequency multiplication crystal and said radiation generated by said second frequency multiplication crystal and outputting an output beam having radiation at a wavelength of approximately 193 nm.
A system for generating substantially monochromatic ultraviolet laser radiation at a wavelength of approximately 193 nm, comprising:
- a first laser source providing a first primary laser beam comprising pulses of laser radiation at a first wavelength;
- a harmonic generator receiving said first primary laser beam and outputting an intermediate beam;
- a second laser source providing a second primary laser beam comprising pulses of laser radiation at a wavelength that is different from the wavelength of said first primary laser beam;
- a first frequency mixing crystal receiving said intermediate beam from said harmonic generator and second primary laser beam and outputting an output beam having radiation at a wavelength of approximately 193 nm.
A system for generating substantially monochromatic ultraviolet laser radiation at a wavelength of approximately 193 nm, comprising:
- a first laser source providing a first primary laser beam comprising pulses of laser radiation at a first wavelength;
- a second laser source providing a second primary laser beam comprising pulses of laser radiation at a wavelength that is different from the wavelength of said first primary laser beam;
- at least one frequency multiplication crystal shaped and arranged to generate radiation at a wavelength of approximately 355 nm from said first primary laser beam;
- a frequency mixing crystal receiving said approximately 355 nm radiation and said second primary laser beam and outputting an output beam having radiation at a wavelength of approximately 248 nm.
Dependencies are inferred from the claim text.