EUV Pellicle Film Back-Etching to Reduce Dust Attachment
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Solution Overview
Problem
Pellicles for EUV lithography are prone to contamination with dust during production processes such as trimming, transportation, and handling due to the formation of eaves-like portions during conventional back-etching, which are difficult to remove without damaging the pellicle film.
Innovation Solution
A method involving the use of a metal mask, such as chromium, to facilitate back-etching, followed by removal of the metal mask, and optional surface metal coating layer to minimize dust attachment, along with chamfering and hole formation to prevent chip formation and improve handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional back-etching is used to remove substrate, then the pellicle film can be formed, but eaves-like portions are formed which are difficult to remove and cause dust contamination
Solution Approach 1:
The substrate removal process is segmented into two distinct stages: first removing the sacrificial substrate layer, then separately removing the eaves-like portions. This segmentation allows each removal step to be optimized independently, preventing dust contamination while maintaining manufacturing feasibility.
Solution Approach 2:
A sacrificial substrate layer is introduced as an intermediary element that facilitates the etching process. This sacrificial layer is selectively removed first, enabling subsequent removal of eaves-like portions without directly etching the pellicle film, thereby preventing dust contamination.
2Use of energy by moving object
If the pellicle film is made extremely thin for EUV lithography, then EUV light transmission is improved, but the film becomes more susceptible to dust attachment and damage
Solution Approach 1:
The pellicle film is pre-coated with a protective layer before the etching and handling processes. This protective coating acts as a cushion that prevents dust attachment and mechanical damage during manufacturing, while being removable afterward to maintain EUV light transmission.
Solution Approach 2:
A flexible protective coating is applied to the extremely thin pellicle film. This flexible shell provides mechanical protection and dust resistance without significantly impeding EUV light transmission, allowing the film to maintain its required thinness for EUV applications.
3Ease of operation
If the pellicle frame is trimmed and handled during production, then the pellicle can be assembled, but dust attaches to the pellicle film during these processes
Solution Approach 1:
A disposable protective coating is applied to the pellicle film during handling and assembly operations. This coating is inexpensive and easily removed afterward, providing temporary protection against dust attachment during necessary manual operations while not compromising the final product quality.
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 method produces a pellicle with significantly reduced dust attachment, enhancing the pellicle's durability and handling, and handling, and improves the pellicle's durability and durability, effectively addressing the limitations of existing pellicle production methods.
Implementation Method 1
removing a part of the substrate from the side of the metal mask
Implementation Method 2
removing the metal mask
Implementation Method 3
forming a pellicle film on a substrate
Data Source
Figure 1(a)~1(c)
Figure 2
Figure 3(a)~3(c)
AI summary
Provided is a pellicle film, a pellicle frame and a pellicle for EUV decreased in the amount of dust or the like attached thereto, and a method for producing the same. Provided is a method for producing a pellicle including forming a pellicle film (202) above a substrate (200); forming a metal mask (204) on a surface of the substrate opposite to a surface having the pellicle film formed thereon; removing a part of the substrate from the side of the metal mask; and removing the metal mask. In an embodiment, the present invention provides a pellicle film, a pellicle frame and a pellicle for EUV decreased in the amount of dust or the like attached thereto, and a method for producing the same.