Narrowed-Line Laser Apparatus Spectral Linewidth Control
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Solution Overview
Problem
Current semiconductor exposure technologies face challenges in achieving high resolution due to chromatic aberrations caused by wide spectral linewidths of KrF and ArF excimer laser apparatuses, which are exacerbated by liquid-immersion exposure methods, leading to decreased resolution and accuracy in semiconductor manufacturing.
Innovation Solution
A narrowed-line laser apparatus is developed, featuring a spectral width changer with a first and second optical element holder, an elastic member, and a guide section that allows precise movement, reducing spectral linewidth and chromatic aberrations by adjusting the optical elements to maintain precise beam characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If liquid-immersion exposure is used to improve resolution, then the apparent wavelength is shortened, but chromatic aberrations increase due to wide spectral linewidth
Solution Approach 1:
The patent changes the spectral parameter of the laser light by introducing a line narrowing module with optical elements (etalon or grating) that selectively transmit a narrow wavelength band, thereby reducing the spectral linewidth from 350-400 pm to a much narrower range and eliminating chromatic aberrations while maintaining the benefits of liquid-immersion exposure
2Manufacturing precision
If spectral linewidth is narrowed to reduce chromatic aberrations, then resolution is improved, but device complexity increases due to additional optical components
Solution Approach 1:
The patent combines the line narrowing function with the existing laser resonator structure by integrating the optical elements (etalon or grating) as a line narrowing module within the resonator, rather than adding a completely separate system, thereby achieving spectral narrowing while minimizing additional complexity
3Object-affected harmful factors
If optical elements are added to narrow spectral width, then chromatic aberrations are reduced, but alignment precision requirements increase
Solution Approach 1:
The patent incorporates feedback mechanisms through precise mounting structures and adjustment mechanisms for the optical elements in the line narrowing module, allowing for accurate alignment and maintaining stable optical paths despite the added complexity of multiple optical components
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 solution effectively narrows the spectral linewidth, reducing chromatic aberrations and enhancing the resolution of the semiconductor exposure process, thereby improving the precision and accuracy of semiconductor manufacturing.
Implementation Method 1
an elastic member disposed in a position which is located between the first holder and the second holder
Implementation Method 2
The line narrowing element may, for example, be an etalon or a grating
Implementation Method 3
A line narrowing module including a line narrowing element is therefore provided in the laser resonator of the gas laser apparatus, and the line narrowing module narrows the spectral width
Implementation Method 4
In the liquid-immersion exposure, since the refractive index of the gap between the projection lens and the wafer changes, the apparent wavelength of the light from the light source for exposure is shortened
Data Source
AI summary
An optical element moving apparatus includes a first holder configured to hold a first optical element, a second holder configured to hold a second optical element and having an inclination that inclines with respect to a first direction in which the second holder approaches the first holder, a guide section configured to be capable of moving the second holder in a direction parallel to the first direction, and an elastic member disposed in a position which is located between the first holder and the second holder and through which a first plane passes, the first plane intersecting the inclination at right angles and being parallel to the first direction.