Blank Mask Fabrication Chuck Air Ejection System
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current photomask fabrication techniques face challenges in achieving high precision and low defect rates, particularly due to light diffraction issues at the edges of binary masks and contamination from process by-products during the exposure process.
Innovation Solution
An apparatus and method for fabricating a blank mask that includes a rotatable chuck with a guide part and a by-product removal system using compressed air to eject process by-products from the space between the optical substrate and the guide part, minimizing contamination and improving precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a binary mask with fine patterns is used, then the circuit pattern refinement is improved, but light diffraction at the edges causes pattern defects
Solution Approach 1:
The patent converts the harmful light diffraction effect into a beneficial phase shift effect. By introducing a phase shift layer that creates a 180-degree phase difference, the diffracted light from fine patterns is transformed into constructive interference that enhances pattern definition rather than creating defects
Solution Approach 2:
The patent uses a composite mask structure combining a light-transmissive substrate with a phase shift layer made of materials having specific refractive index and thickness properties. This composite structure enables both fine pattern transmission and diffraction control through the phase shift effect
2Productivity
If a photomask is used for extended periods, then productivity is improved, but contamination from process by-products reduces the number of uses
Solution Approach 1:
The patent extracts and removes process by-products from the exposure space using a by-product removal part with suction holes. This active removal system prevents contamination accumulation on the photomask surface, thereby extending the mask's usable life and maintaining productivity
Solution Approach 2:
The patent implements a feedback mechanism where the state of the exposure space is continuously monitored and the by-product removal system adjusts its operation accordingly. This ensures optimal contamination control throughout the photomask's usage period
3Manufacturing precision
If the space between the optical substrate and guide part is reduced, then manufacturing precision is improved, but process by-products accumulate in the narrow space
Solution Approach 1:
The patent extracts process by-products from the narrow space between the optical substrate and guide part through suction holes positioned in the by-product removal part. This allows maintaining a small gap for precision while actively removing accumulated contaminants
Solution Approach 2:
The patent introduces an intermediary airflow field that facilitates the removal of process by-products from the narrow gap. The airflow acts as a mediator to transport contaminants from the confined space to the evacuation system without requiring increased spacing
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 removes fine particle by-products, preventing contamination and enhancing the precision and performance of the blank mask, thereby reducing defect occurrence and improving the number of uses.
Implementation Method 1
an air pump for spraying compressed air to a space between a side surface of the optical substrate and the guide part
Data Source
AI summary
Disclosed is an apparatus for fabricating a blank mask, the apparatus including: a chamber; and a rotatable chuck placed inside the chamber, wherein the rotatable chuck includes: a support part configured to support an optical substrate placed on the support part; a guide part disposed on a side of the optical substrate and connected to the support part; and an air pump for spraying compressed air to a space between a side surface of the optical substrate and the guide part.