Substrate Spin Coating Shield for Uniform Film Deposition
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Solution Overview
Problem
The existing spin coating methods for polymers on substrates face issues with non-uniform coating due to aerosols redepositing on the substrate surface, especially when the opposite side of the substrate cannot be contacted, such as during backside coating, leading to contamination and damage.
Innovation Solution
A substrate coating system with a shield member that creates a solvent-rich ambient using a central chamber and a peripheral gas flow to prevent aerosols from redepositing on the substrate during spin coating, utilizing a funnel-shaped shield member positioned close to the substrate to control the environment and airflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a pin is used to support the substrate during spin coating, then the substrate can be supported without contact on the opposite side, but the pin creates unwanted turbulence causing aerosols to redeposit onto the substrate surface
Solution Approach 1:
A gas flow is introduced as an intermediary medium between the pin support structure and the substrate surface. The gas flow carries aerosols away from the substrate surface, preventing redeposition while allowing the pin to maintain mechanical support without direct contact with the coated surface
Solution Approach 2:
A gas stream is used to create a protective atmosphere around the substrate during spin coating. The gas flow dynamically prevents aerosol deposition by continuously moving away from the substrate surface, eliminating the need for complex mechanical shielding structures
2Manufacturing precision
If the substrate is spun at high speed to remove excess polymer, then a thin uniform film is formed, but aerosols are generated and may redeposit onto the substrate surface
Solution Approach 1:
The aerosols generated during high-speed spinning, which would normally be harmful, are redirected by the gas flow to be carried away from the substrate surface. The harmful aerosol generation is converted into a beneficial effect where the same aerosols are used to maintain a controlled atmosphere that prevents unwanted deposition
Solution Approach 2:
A controlled gas atmosphere is created around the substrate during spin coating. This inert environment prevents aerosols from contacting and depositing on the substrate surface, allowing high-speed spinning to proceed without contamination while maintaining film uniformity
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 ensures uniform coating by preventing aerosol redeposition, maintaining substrate integrity, and avoiding contamination, particularly during backside coating without contacting the non-coated surface.
Implementation Method 1
the solvent vapor is introduced into the central chamber of the shield member to create a solvent rich ambient around the substrate
Implementation Method 2
the gas flows through the peripheral chamber of the shield member and towards a peripheral edge portion of the substrate
Implementation Method 3
excess polymer is spun off the wafer leaving a relatively thin film of polymer on the top of the wafer
Data Source
AI summary
A system and/or method for coating a substrate. The method may include placing a substrate on a chuck with a first side of the substrate facing upward and a second side of the substrate facing downward. A coating material may be dispensed onto the first side of the substrate. A first gas may flow through a peripheral chamber of a shield member, the first gas exiting the peripheral chamber through an outlet and flowing towards the first side of the substrate. The substrate may be rotated about a rotational axis to form a film of the coating material on the first side of the substrate.