Phase-Matched Solid-State Laser for Narrow Linewidth Exposure
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Solution Overview
Problem
Chromatic aberration occurs in semiconductor exposure apparatuses due to the wide spectrum line width of KrF and ArF excimer laser beams, leading to decreased resolving power, which is addressed by incorporating a line narrowing module to narrow the spectrum line width.
Innovation Solution
A solid-state laser system with a first and second laser apparatus, non-linear crystals, adjustment units, and a processor for controlling phase matching based on light intensity, generating and optimizing wavelength-converted light to improve resolving power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a line narrowing module is incorporated to narrow the spectrum line width, then chromatic aberration is reduced and resolving power is improved, but device complexity increases
Solution Approach 1:
The patent replaces the conventional mechanical line narrowing module (LNM) with a solid-state laser system that generates laser beams with inherently narrow spectrum line width. This substitution eliminates the need for complex mechanical narrowing components while achieving the same or better spectral precision, thereby resolving the contradiction between improving resolving power and reducing device complexity
Solution Approach 2:
The patent changes the fundamental parameter of spectrum line width by using solid-state laser sources that naturally emit with narrow spectral bandwidth. This parameter change allows achieving high resolving power without requiring additional line narrowing modules, thus improving manufacturing precision while avoiding increased device complexity
2Object-affected harmful factors
If the spectrum line width is narrowed using a line narrowing module, then chromatic aberration is reduced, but the device structure becomes more complex and adjustment becomes more difficult
Solution Approach 1:
The patent substitutes the mechanical line narrowing module that causes structural complexity and adjustment difficulty with a solid-state laser system that inherently produces narrow spectrum line width. This eliminates the harmful chromatic aberration without introducing complex mechanical structures or adjustment mechanisms
3Manufacturing precision
If a line narrowing module is added to the laser resonator, then the spectrum line width is narrowed, but ease of operation decreases due to additional adjustment requirements
Solution Approach 1:
The patent replaces the line narrowing module requiring manual adjustment with a solid-state laser system where the narrow spectrum line width is achieved through the inherent properties of the laser medium and cavity design. This substitution maintains high spectral precision while significantly improving ease of operation by eliminating complex adjustment procedures
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
The system effectively narrows the spectrum line width, reducing chromatic aberration and enhancing the resolving power of semiconductor exposure apparatuses.
Implementation Method 1
a first non-linear crystal that generates first wavelength-converted light based on the first laser beam
Implementation Method 2
a second non-linear crystal that is disposed on an optical path of the first wavelength-converted light and generates second wavelength-converted light based on the first wavelength-converted light and the second laser beam
Data Source
AI summary
A solid-state laser system according to an aspect of the present disclosure includes a first non-linear crystal that generates first wavelength-converted light based on a first laser beam, a first adjustment unit configured to perform phase matching of the first wavelength-converted light in the first non-linear crystal, a second non-linear crystal that generates second wavelength-converted light based on a second laser beam and the first wavelength-converted light, a second adjustment unit configured to perform phase matching of the second wavelength-converted light in the second non-linear crystal, a light detection unit configured to detect light having a selected wavelength, and a processor configured to control the first adjustment unit based on intensity of at least one of the first wavelength-converted light and the first laser beam and to control the second adjustment unit based on intensity of at least one of the second wavelength-converted light and the first wavelength-converted light.