Mirror-Symmetric Scrubber Brush Control for Substrate Cleaning
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Solution Overview
Problem
Conventional cleaning processes for semiconductor substrates lack effective control over the movement and force applied by scrubber brushes, which can lead to substrate damage during the cleaning process.
Innovation Solution
A substrate cleaner apparatus and method utilizing two scrubber brush assemblies that move in mirror symmetry, with a positioning assembly to adjust their positions simultaneously, ensuring symmetrical forces are applied to opposite surfaces of the substrate, thereby reducing the risk of damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional scrubber brushes are used to clean substrate surfaces, then cleaning capability is achieved, but force control is insufficient leading to substrate damage
Solution Approach 1:
The scrubber brush assembly incorporates a compliant mechanism that dynamically adjusts the contact force between the brush and substrate. The mechanism includes a brush carrier that can move relative to the drive shaft, allowing the brush to self-adjust its position and applied force based on substrate characteristics, thereby preventing damage while maintaining cleaning effectiveness
Solution Approach 2:
The system employs force sensors that continuously monitor the contact force between the scrubber brush and substrate. This feedback is transmitted to a controller that adjusts the brush position and rotation speed in real-time to maintain optimal cleaning force without exceeding damage thresholds, solving the force control issue
2Manufacturing precision
If scrubber brushes approach substrate from both front and back sides, then cleaning coverage is improved, but force symmetry control becomes difficult
Solution Approach 1:
The patent employs symmetric design principles where identical scrubber brush assemblies are positioned on opposite sides of the substrate holder. Both brushes are configured with matching parameters (rotation speed, contact force, brush dimensions) to ensure symmetric cleaning action, which simplifies the control system while achieving uniform cleaning across the substrate surface
Solution Approach 2:
The control system integrates the positioning and force control of both scrubber brushes into a single coordinated system. The controller simultaneously manages both brush assemblies, ensuring they move and apply force in a synchronized manner, thereby achieving uniform cleaning without requiring complex independent control mechanisms for each brush
3Manufacturing precision
If mechanical scrubbing devices are used with polishing pads, then planarization is achieved, but residual particles and polishing solution remain on substrate
Solution Approach 1:
The cleaning system is integrated into the polishing process as a continuous operation. After the substrate is polished, it immediately transitions to the cleaning stage without interruption, where the scrubber brushes continuously remove polishing residues and particles throughout the substrate surface, ensuring complete removal of contaminants while maintaining the achieved flatness
Solution Approach 2:
The patent introduces a fluid delivery system that provides cleaning solution to the scrubber brush during the cleaning process. This intermediary fluid helps loosen and remove polishing residues and particles more effectively, facilitating complete contamination removal while the mechanical brush provides the necessary mechanical action
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 symmetrical movement of scrubber brush assemblies allows for controlled and uniform cleaning forces, minimizing substrate damage and improving the cleaning process efficiency.
Implementation Method 1
scrubbing the substrate surfaces with mechanical scrubbing devices using brushes... apply a brushing force against the substrate
Implementation Method 2
positioning assembly configured to simultaneously adjust positions of the first and second scrubber brush assemblies... makes substantially the same amount of adjustment to the first and second scrubber brush assemblies in mirror symmetry
Data Source
AI summary
Embodiments of the present invention relates to an apparatus and method for cleaning a substrate using scrubber brushes. One embodiment of the present invention provides a substrate cleaner comprises two scrubber brush assemblies movably disposed in a processing volume. The two scrubber brush assemblies are configured to contact and clean opposite surfaces of a substrate disposed in the processing volume. The substrate cleaner also comprises a positioning assembly configured to simultaneously adjust positions of the two scrubber brush assemblies, wherein the positioning assembly makes substantially the same amount of adjustment to the first and second scrubber brush assemblies in mirror symmetry.