Electrostatic Particle Removal for Metrology Tool Components
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Solution Overview
Problem
Contaminant particles such as polyester or cellulose fibers can attach to components of metrology tools, leading to damage and reduced accuracy, and existing cleaning methods can introduce further contamination or damage components.
Innovation Solution
An apparatus with a collection region and an electric field generator that determines and applies an electric field to attract and remove contaminant particles, using a processor to determine the polarity and magnitude of the applied electric field based on the ambient electric field, and a vacuum pump for particle removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional cleaning methods (wipes, solvents) are used to remove contaminant particles, then particles can be removed from components, but further contamination may be introduced or components may be damaged
Solution Approach 1:
The patent replaces mechanical cleaning methods (wipes, brushes, solvents) with an electrostatic field-based removal system. The electric field generator creates an electric field that attracts contaminant particles to a collection region, eliminating the need for physical contact and thereby preventing mechanical damage and secondary contamination.
Solution Approach 2:
The patent introduces an electric field as an intermediary between the contaminant particles and the collection region. This intermediary force field enables particle removal without direct mechanical interaction, serving as a non-contact mediator that transfers particles from the component surface to the collection region safely.
2Manufacturing precision
If frequent measurements are performed to maintain manufacturing precision, then process control and verification are improved, but contaminant particles may accumulate on components
Solution Approach 1:
The patent enables continuous or frequent particle removal operations by maintaining a clean component surface through the electrostatic field system. The electric field generator can operate repeatedly without causing wear or damage, allowing continuous measurement and cleaning cycles to maintain manufacturing precision indefinitely.
Solution Approach 2:
The system allows the metrology tool to self-clean its own components using the integrated electric field generator and collection region, eliminating the need for external manual cleaning interventions that could introduce contamination or cause damage during frequent measurement operations.
3Object-affected harmful factors
If manual cleaning procedures are implemented to remove particles, then particle removal is achieved, but downtime increases and productivity decreases
Solution Approach 1:
The patent replaces time-consuming manual cleaning procedures with an automated electrostatic field-based system. The electric field generator and collection region enable rapid particle removal without requiring disassembly, manual handling, or complex cleaning protocols, significantly reducing tool downtime and maintaining productivity.
4Measurement precision
If cleaning operations are performed to maintain component cleanliness, then measurement accuracy is preserved, but complexity of the cleaning system increases
Solution Approach 1:
The patent extracts the essential cleaning function into a simple electrostatic field generation system with a collection region. By removing complex mechanical cleaning mechanisms, solvents, and manual procedures, the system achieves component cleanliness maintenance through a single electric field generator and collection region, reducing overall system complexity while preserving measurement accuracy.
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
Effectively removes contaminant particles without damaging components, reducing downtime and maintaining tool accuracy, while minimizing the risk of spreading contamination.
Implementation Method 1
an electric field generator configured to establish an applied electric field between the collection region and the component to cause the particles to be transported from the component to the collection region
Implementation Method 2
the contaminant particles giving rise to an ambient electric field
Data Source
AI summary
An apparatus (300) for removing contaminant particles (205) from a component (202, 204) of an apparatus (140, MT), the contaminant particles giving rise to an ambient electric field (E), the apparatus comprising: a collection region (301) for attracting the particles, wherein the ambient electric field is at least between the component and the collection region; and an electric field generator configured to establish an applied electric field between the collection region and the component to cause the particles to be transported from the component to the collection region, wherein the electric field generator is configured to determine the polarity of the applied electric field based on the ambient electric field.