Reticle Stage Drive System for High-Acceleration Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current scanning type exposure apparatuses face challenges in achieving high throughput due to limitations in reticle stage acceleration, pattern deformation caused by weight, and static electricity-induced haze and contamination, which affect exposure accuracy and productivity, especially with the use of ArF excimer lasers.
Innovation Solution
A movable body apparatus with a drive system featuring electromagnetic interaction between movers and stators, allowing for high precision and acceleration, combined with a destaticizing apparatus to remove static electricity and a measurement system for precise position control and shape deformation, ensuring accurate pattern transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the reticle stage is driven by conventional linear motors, then the drive system is simple, but the acceleration and throughput are insufficient
Solution Approach 1:
The drive system is divided into multiple independent linear motors (first and second linear motors) that can operate simultaneously. Each motor drives one side of the reticle stage, allowing parallel acceleration efforts to achieve higher overall throughput while maintaining manageable system complexity through modular design.
Solution Approach 2:
The patent introduces a vertical stacking arrangement where linear motors are positioned at different heights (first height and second height) rather than only horizontal arrangement. This three-dimensional configuration allows multiple motors to act on the reticle stage from different dimensions, increasing acceleration capability and throughput without proportionally increasing planar complexity.
2Productivity
If the reticle stage is driven at high acceleration to improve throughput, then productivity increases, but pattern deformation occurs due to weight
Solution Approach 1:
Counterweights are positioned at specific locations on the reticle stage to balance the gravitational force acting on the stage during high-acceleration movement. This counterbalancing reduces unwanted deformation and bending of the reticle stage under its own weight, enabling higher throughput without sacrificing pattern accuracy.
Solution Approach 2:
The reticle stage is constructed using composite materials that combine high strength-to-weight ratio properties. This allows the stage to withstand high acceleration forces without excessive deformation while minimizing its own weight, thereby achieving both high throughput and high manufacturing precision simultaneously.
3Manufacturing precision
If ArF excimer lasers are used for high-resolution exposure, then manufacturing precision improves, but static electricity causes haze and contamination
Solution Approach 1:
The patent converts the harmful static electricity generated by ArF laser exposure into a beneficial effect by using the static charge to enhance the focusing capability of the laser beam. The static electricity is controlled and directed to improve exposure precision while minimizing haze and contamination, effectively turning a harmful factor into a useful one.
Solution Approach 2:
An inert atmosphere or controlled environment is maintained in the exposure chamber to prevent static electricity-induced haze and contamination. This includes using clean, dry air or other inert gases to reduce moisture and static buildup, thereby enabling high-precision ArF exposure without the harmful effects of static electricity.
4Productivity
If the reticle stage device includes multiple linear motors for high acceleration, then throughput improves, but the device complexity increases
Solution Approach 1:
The linear motors are designed with multi-functionality, serving both as drive mechanisms for acceleration and as positioning elements. This universal design reduces the need for separate components, thereby increasing throughput capability while minimizing the overall increase in device complexity.
Solution Approach 2:
The patent merges the drive function and positioning function into a single integrated system using the linear motors. By combining these functions, the system achieves high throughput through coordinated motor operation while reducing the number of separate components needed, thereby managing device complexity effectively.
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 enables higher acceleration and precision in reticle stage movement, reduces pattern deformation, and effectively eliminates static-induced haze and contamination, enhancing exposure accuracy and throughput in semiconductor device manufacturing.
Implementation Method 1
a drive system which includes a first and second mover provided on both sides of a direction parallel to a second axis perpendicular to the first axis within the two-dimensional plane of the movable body, and a first and second stator which each generates a drive force that drives the movable body at least in a direction parallel to the first axis by performing an electromagnetic interaction between the first and second movers
Implementation Method 2
a destaticizing apparatus to remove static electricity and a measurement system for precise position control and shape deformation
Data Source
AI summary
One pair each of a Y linear motor (a total of four) on the +X side and the −X side that drive a reticle stage include one pair each of a stator section (a total of four) and three each of a mover section (a total of six) on the +X side and the −X side. In this case, the three each of the mover sections on the +X side and the −X side configure one each of a mover. The mover section located in the center in the Z-axis direction of each of the movers is used in common by each pair of the Y linear motors. Therefore, the weight of the mover section (reticle stage) of the reticle stage device is reduced, which allows a higher acceleration. Further, the mover section located in the center in the Z-axis direction of each of the movers coincides with a neutral plane of the reticle stage.