Lithography Clamp Cleaning Reticle for In-Situ Particle Removal
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Solution Overview
Problem
Existing cleaning methods for lithography apparatus clamps are inefficient, requiring significant downtime, exposure to ambient conditions, and inadequate removal of small particle contamination, which can lead to performance degradation and overlay issues in semiconductor manufacturing.
Innovation Solution
A cleaning system comprising a body with cleaning features patterned on its clamp-facing surface, designed to approximate the locations and dimensions of contamination particles on the clamp, allowing for effective removal through relative movement between the cleaning features and the clamp without disassembling the lithography apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional cleaning methods are used for lithography apparatus clamps, then cleaning can be performed, but significant downtime is required and the apparatus must be disassembled or exposed to ambient conditions
Solution Approach 1:
The cleaning system is designed to be automatically handled by the lithography apparatus's existing tool handler, allowing the system to clean itself without external intervention. The cleaning reticle is automatically inserted, positioned, and removed by the apparatus's own handling mechanisms, eliminating the need for manual disassembly and reducing downtime significantly.
Solution Approach 2:
The cleaning reticle is designed to fit within the existing reticle handling infrastructure of the lithography apparatus. It nests into the tool handler's gripper and is positioned using the apparatus's existing positioning mechanisms, allowing the cleaning function to be integrated without adding external cleaning equipment that would require separate installation and operation.
2Reliability
If traditional cleaning methods are used, then cleaning can be performed, but the apparatus must be exposed to ambient conditions which can introduce new contaminants
Solution Approach 1:
The cleaning operation is performed entirely within the vacuum environment of the lithography apparatus. The cleaning reticle is inserted and processed without breaking vacuum, maintaining the inert vacuum atmosphere that prevents introduction of ambient contaminants such as dust, moisture, and other airborne particles that would otherwise contaminate the clamp and optical surfaces.
Solution Approach 2:
The cleaning reticle acts as an intermediary carrier that brings cleaning features into the vacuum environment without requiring the vacuum environment to be breached. It serves as a mediator that enables cleaning functionality while maintaining the integrity of the vacuum seal, preventing ambient contamination from entering the apparatus.
3Reliability
If manual cleaning apparatus are used, then cleaning can be performed, but potential damage to clamps can occur due to mishandling
Solution Approach 1:
The lithography apparatus's existing tool handler and positioning mechanisms perform the cleaning operation automatically, eliminating manual handling of the clamp. The system uses the apparatus's own precision positioning and handling capabilities to manipulate the cleaning reticle and clamp with controlled forces, preventing damage that would occur with manual cleaning tools and procedures.
Solution Approach 2:
Manual mechanical cleaning tools are replaced with an automated cleaning system that uses the lithography apparatus's existing precision mechanical handling mechanisms. The tool handler grips and positions the cleaning reticle with precision, and the relative movement between the cleaning reticle and clamp is controlled by the apparatus's positioning system, replacing rough manual handling with precision automated control.
4Manufacturing precision
If cleaning features are positioned to match contamination locations, then cleaning effectiveness is improved, but the cleaning system becomes more complex
Solution Approach 1:
The cleaning features on the cleaning reticle are designed to approximate the locations and dimensions of typical contamination particles on the clamp based on observed contamination patterns. Rather than creating a perfectly customized cleaning pattern for each specific contamination instance, the system uses a copied approximation of typical contamination locations that can be manufactured using standard lithographic patterning techniques, balancing effectiveness with manufacturability.
Data Source
AI summary
A system for cleaning contamination particles from a clamp of a lithography apparatus. The system includes a body configured to be inserted into the lithography apparatus, engaged by a tool handler of the lithography apparatus, and positioned by the tool handler for clamping by the clamp. Cleaning features are patterned on a clamp facing surface of the body. Locations and dimensions of the cleaning features on the clamp facing surface approximate locations and dimensions of the contamination particles on the clamp, such that relative movement between the cleaning features and the clamp cleans the contamination particles from the clamp. For example, the locations of the cleaning features on the clamp facing surface can correspond to object contact areas (e.g., burls) on the clamp where the contamination particles are located. The dimensions of the cleaning features comprise a specific pitch, a line width, and a thickness.