Spatial Light Modulator for Multilevel Pupil Luminance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional spatial light modulators fail to achieve multilevel pupil luminance distributions where light intensities in different zones on the illumination pupil plane can be optionally controlled, limiting their application in advanced illumination methods and device manufacturing.
Innovation Solution
An illumination apparatus comprising a spatial light modulator with independently controllable reflecting surfaces and a condensing optical system that converts light angle distributions into position distributions on the illumination pupil plane, allowing for precise control of light intensity across the pupil plane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a spatial filter with transparent regions is used to obtain multilevel pupil luminance distribution, then light intensity distribution is improved, but control flexibility over individual zones is lost
Solution Approach 1:
The spatial light modulator divides the illumination pupil plane into multiple independently controllable zones or pixels. Each zone can be individually addressed and controlled to achieve different light intensities, enabling both multilevel luminance distribution and flexible zone-by-zone control that was not possible with conventional spatial filters
Solution Approach 2:
The spatial light modulator provides dynamic control of pupil luminance distribution by allowing real-time adjustment of light intensity in each zone through electronic control signals. This dynamic capability enables flexible reconfiguration of illumination patterns without physical changes to the optical system
2Adaptability or versatility
If conventional spatial light modulators are used, then basic spatial modulation is achieved, but multilevel pupil luminance distribution with optional zone control cannot be formed
Solution Approach 1:
The invention applies local quality by allowing different regions (zones) of the illumination pupil plane to have different light intensities independently controlled. Each zone can be optimized with specific luminance levels tailored to the required illumination pattern, achieving precise control over the overall illumination distribution
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
Enables the formation of multilevel pupil luminance distributions, enhancing the capabilities of illumination systems for exposure applications and device manufacturing by allowing for customizable light intensity patterns on the illumination target surface.
Implementation Method 1
The condensing optical system condenses light from the reflecting surfaces of the spatial light modulator to form a predetermined light intensity distribution on the illumination pupil plane
Implementation Method 2
The spatial light modulator has a plurality of reflecting surfaces whose postures are controlled independently of each other
Data Source
AI summary
To optionally forming a multilevel light intensity distribution on an illumination pupil plane, the illumination apparatus implements Köhler illumination on an illumination target surface, using as a light source the light intensity distribution formed on the illumination pupil plane on the basis of light from a light source. The illumination apparatus has a spatial light modulator, a condensing optical system, and a controller. The spatial light modulator has reflecting surfaces which are two-dimensionally arranged and postures of which can be controlled independently of each other. The condensing optical system condenses light from the reflecting surfaces to form a predetermined light intensity distribution on the illumination pupil plane. The controller controls the number of reflecting surfaces contributing to arriving light, for each of points on the illumination pupil plane forming the light intensity distribution, according to a light intensity distribution to be formed on the illumination pupil plane.