Conjugate Common Optical Path Lithography Lens Design
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Solution Overview
Problem
Current lithography lens sets face challenges due to their large volume, complex manufacture, and high cost, primarily because they require multiple non-spherical mirrors and faces, which complicate assembly and increase production costs.
Innovation Solution
A conjugate common light path lithography lens set is developed using a spherical and folded assembly with four spherical lenses and a spherical reflecting mirror, along with planar mirrors, to reduce component complexity and material usage, allowing for easier calibration and reduced chromatic aberration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If full refractive lens or long optical extended lens is used, then lithography function is achieved, but volume becomes large
Solution Approach 1:
The patent implements a folded optical path where light traverses the same physical space multiple times through sequential reflections. The optical path is nested within itself, allowing the effective optical length to exceed the physical dimensions of the lens set, thereby reducing overall volume while maintaining lithography functionality.
Solution Approach 2:
The patent transitions from a linear optical path to a three-dimensional folded path using multiple reflecting mirrors at different angles and positions. By utilizing spatial dimensions vertically and diagonally, the optical path is compacted into a smaller footprint while preserving the required optical path length for lithography.
2Reliability
If long optical extended lens with multiple faces is used, then device count is reduced, but manufacture and assembly become difficult
Solution Approach 1:
The patent divides the optical system into discrete modular components: spherical lenses with standard surfaces and separate reflecting mirrors with planar or spherical surfaces. Each component can be manufactured independently using standard optical fabrication techniques, avoiding the need to create complex multi-faced monolithic lenses, thereby simplifying manufacture and assembly.
Solution Approach 2:
The patent specifies that all lenses have spherical surfaces and mirrors have planar or spherical surfaces, which are the simplest optical surfaces to manufacture with high precision. This avoids the need for complex aspherical or freeform surfaces, making each component easier to fabricate while maintaining optical performance through proper arrangement.
3Loss of substance
If non-spherical mirrors are used to reduce light path, then material usage is reduced, but manufacture precision requirement increases
Solution Approach 1:
The patent deliberately chooses spherical surfaces for all lenses and planar or spherical surfaces for mirrors, which are the easiest surfaces to manufacture with high precision. By avoiding complex non-spherical surfaces, the patent reduces manufacturing precision requirements while still achieving compact light path folding through the geometric arrangement of multiple simple surfaces.
Solution Approach 2:
The patent optimizes the number, position, and orientation parameters of the reflecting mirrors to achieve compact light path folding. By carefully adjusting these geometric parameters rather than complicating the mirror surface shapes, the patent reduces material usage while maintaining manufacturability with standard precision requirements.
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 results in a more cost-effective, easier-to-manufacture lens set with reduced components, improved calibration, minimized chromatic aberration, and optimized aperture, achieving higher image resolution and reduced production costs.
Implementation Method 1
a first spherical lens, a second spherical lens, a third spherical lens, and a fourth spherical lens arranged sequentially, the first and second spherical lens providing a curvature and a calibrated planatism, and the third and fourth spherical lens being used to calibrate an astigmatism and a curvature of field
Implementation Method 2
a spherical reflecting mirror, arranged below a fourth spherical lens, to reflect a light path and control a dimension of a numerical aperture
Implementation Method 3
a first and second planar reflecting mirrors, inclinedly arranged above the first spherical lens to guide a light path
Data Source
AI summary
A conjugate common light path lithography lens set includes a first, second, third, and fourth spherical mirrors, arranged sequentially, a spherical reflecting mirror arranged below the fourth spherical mirror, a first and second planar reflecting mirrors, inclinedly arranged above the first spherical mirror, so that a conjugate telecentric component pattern is formed to maintain an pattern of an object to have a non-deformed pattern after experiencing these optical components. As such, the omni-spherical mirror set and two kinds of optical material are mutually arranged to form the novel conjugate common light path lithography lens set. This may further achieve the function of the lithography lens, and have a direct effect on the manufacturing cost. And, the efficacies of reduced component number, easier manufacture of the optical components (satisfied with the lens manufacturing's experience equation), easier calibration, reduced chromatic abberation, optimized aperature F/#, and a reduced cost may be achieved.