Substrate Protective Film Removal for Vacuum Suction Processing
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Solution Overview
Problem
Existing substrate processing methods result in contact marks and contamination of the rear surface due to vacuum suction, particularly in EUV lithography, and require large-scale cleaning steps to remove protective films, complicating the process.
Innovation Solution
A substrate processing system with a protective film forming liquid supplying unit, suction unit, and removing liquid supplying unit, allowing for the formation and removal of protective films without immersion in cleaning tanks, and enabling processing on the opposite surface while the film is in place, using a single liquid for removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a protective film is formed on one surface of a substrate and the substrate is held by vacuum suction, then the substrate can be processed without contamination, but the protective film becomes difficult to remove and requires multiple cleaning tanks
Solution Approach 1:
The protective film is designed to change its solubility parameters based on pH. It is insoluble under neutral conditions during processing but becomes soluble when exposed to alkaline removing liquid, enabling easy removal without multiple cleaning tanks
Solution Approach 2:
The protective film uses a composite structure with a water-insoluble base layer providing protection and a water-soluble top layer that dissolves in alkaline conditions, combining protective function with easy removability
2Reliability
If conventional protective films are used, then the substrate surface can be protected, but the films leave residues and require immersion in multiple cleaning solutions
Solution Approach 1:
The film's solubility parameter changes from insoluble to soluble when exposed to alkaline removing liquid, allowing complete dissolution without residues and eliminating the need for multiple immersion cleaning steps
Solution Approach 2:
The soluble top layer is extracted and removed by the alkaline removing liquid, taking with it any adhered particles or contaminants, leaving the substrate surface clean without requiring multiple cleaning solutions
3Productivity
If the substrate is held by suction during processing, then processing can be performed, but contact marks are generated on the suctioned surface
Solution Approach 1:
The substrate surface is segmented into two functional zones: the suctioned surface protected by the insoluble protective film during processing, and the processed surface that receives the actual treatment, allowing suction holding without direct contact marks on the protected surface
Solution Approach 2:
The protective film acts as an intermediary layer between the suction device and the substrate surface, preventing direct contact and eliminating suction-induced contact marks while still allowing vacuum holding
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 system effectively protects the substrate surface with a protective film and simplifies its removal, preventing contamination and reducing the need for multiple cleaning steps, while maintaining the substrate's integrity and efficiency.
Implementation Method 1
a suction unit which suctions the one surface of the substrate
Implementation Method 2
a protective film forming unit which solidifies or hardens the protective film forming liquid to form a protective film on the one surface of the substrate
Implementation Method 3
a removing liquid supplying unit which has a removing liquid discharge port for discharging a removing liquid being capable of the protective film and supplies the removing liquid toward the one surface of the substrate
Data Source
AI summary
A substrate processing system includes a protective film forming liquid supplying unit which supplies a protective film forming liquid to one surface of a substrate, a protective film forming unit which solidifies or hardens the protective film forming liquid and forms a protective film on the one surface of the substrate, a suction unit which suctions the one surface of the substrate, a processing unit which executes predetermined processing with respect to the other surface of the substrate in a state that the one surface of the substrate is suctioned by the suction unit, and a removing liquid supplying unit which has a removing liquid discharge port that discharges a removing liquid being capable of removing the protective film and supplies the removing liquid toward the one surface of the substrate from the removing liquid discharge port.