Laser Light Source Bulb Geometry to Minimize Astigmatism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithographic apparatuses face challenges in minimizing optical aberrations in the wavefront of radiation transmitted through the bulb, leading to reduced brightness and power of the laser-operated light source, which affects the ability to create smaller features on substrates as required by Moore's law.
Innovation Solution
An optical assembly comprising a bulb and a lens that focuses a wavefront of radiation to a virtual object point inside the chamber, with the bulb's design ensuring that the virtual object point, first real image point, and second real image point coincide, reducing or eliminating astigmatism and maintaining the brightness and power of the laser-operated light source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a conventional bulb design is used, then the structure is simple and easy to manufacture, but optical aberrations increase leading to reduced brightness and power
Solution Approach 1:
The bulb design applies different curvature radii to different regions: the first region (where the laser beam enters) has a first curvature radius, while the second region has a second curvature radius that is different from the first. This local variation in optical properties minimizes wavefront aberrations in specific critical regions, thereby maintaining brightness without requiring complete redesign of the entire bulb structure.
Solution Approach 2:
The invention changes the optical parameters of the bulb by specifying different curvature radii for different regions of the bulb. By adjusting these geometric parameters, the wavefront aberrations are minimized, which directly improves the brightness and power output of the laser-operated light source without significantly increasing manufacturing complexity.
2Power
If a conventional bulb design is used, then the manufacturing process is simple, but wavefront aberrations increase leading to reduced power
Solution Approach 1:
The bulb design applies different curvature radii to different regions: the first region (where the laser beam enters) has a first curvature radius, while the second region has a second curvature radius that is different from the first. This local variation in optical properties minimizes wavefront aberrations in specific critical regions, thereby maintaining brightness without requiring complete redesign of the entire bulb structure.
Solution Approach 2:
The invention changes the optical parameters of the bulb by specifying different curvature radii for different regions of the bulb. By adjusting these geometric parameters, the wavefront aberrations are minimized, which directly improves the brightness and power output of the laser-operated light source without significantly increasing manufacturing complexity.
3Use of energy by moving object
If the focused spot size increases due to wavefront aberration, then the energy density decreases, but the bulb design becomes simpler
Solution Approach 1:
The bulb design applies different curvature radii to different regions: the first region (where the laser beam enters) has a first curvature radius, while the second region has a second curvature radius that is different from the first. This local variation in optical properties minimizes wavefront aberrations in specific critical regions, thereby maintaining brightness without requiring complete redesign of the entire bulb structure.
Solution Approach 2:
The invention changes the optical parameters of the bulb by specifying different curvature radii for different regions of the bulb. By adjusting these geometric parameters, the wavefront aberrations are minimized, which directly improves the brightness and power output of the laser-operated light source without significantly increasing manufacturing complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration minimizes astigmatism and maintains or reduces by a factor of 2 the reduction in brightness and power of the laser-operated light source, enabling the creation of smaller features on substrates while adhering to Moore's law.
Implementation Method 1
the bulb is arranged to transmit and refract the wavefront of the radiation
Implementation Method 2
a plasma formed by energizing the ionizable gas
Data Source
AI summary
An optical assembly includes a bulb and a lens for a laser-operated light source. The bulb has a chamber for accommodating an ionizable gas and a plasma formed by energizing the ionizable gas and has a longitudinal axis and a transverse axis perpendicular to the longitudinal axis. In use, the lens is arranged to focus a wavefront of radiation from a laser to a virtual object point located inside the chamber. In use, the bulb is arranged to transmit and refract the wavefront of the radiation to a first real image point in a first cross-section of the longitudinal axis and a second real image point in a second cross-section of the transverse axis. The first real image point and the second real image point are image conjugates of the virtual object point. The virtual object point, the first real image point and the second real image point coincide.