Grounded CMP Fluid Lines With External ESD Wrapper
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Solution Overview
Problem
Static electricity build-up in fluid delivery lines during chemical mechanical polishing (CMP) can lead to electrostatic discharge, damaging components and tubing, particularly in systems using hot gases like steam, and traditional conductive coatings inside the tubing can contaminate the substrate.
Innovation Solution
Use polymer tubing wrapped with a conductive layer, such as copper or carbon, and grounded with a conductive wire to form an electrostatic discharge protective assembly, ensuring the conductive layer is protected by an insulative sheath to prevent contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional conductive coatings are applied inside the tubing to dissipate electrostatic charge, then electrostatic discharge protection is improved, but substrate contamination risk increases
Solution Approach 1:
Instead of applying conductive coating inside the tubing (traditional approach), the patent applies conductive material on the outside surface of the tubing. This inversion of the coating location allows electrostatic dissipation without risking substrate contamination, as the conductive material is isolated from the fluid path by the tubing wall.
Solution Approach 2:
The tubing wall acts as an intermediary barrier between the conductive coating and the fluid/substrate. The conductive coating is applied on the external surface of the tubing, and the tubing material itself serves as the intermediary that prevents direct contact between the conductive material and the fluid, thereby eliminating contamination risk while maintaining ESD protection functionality.
2Reliability
If electrostatic discharge protection is implemented in fluid delivery lines, then component damage from electrostatic discharge is reduced, but device complexity increases
Solution Approach 1:
The electrostatic discharge protection function is merged with the existing tubing structure by applying conductive material directly on the outer surface of the tubing. This integration approach combines the protective function with the fluid delivery component itself, eliminating the need for separate protective devices or complex grounding systems.
Solution Approach 2:
The electrical parameter of the tubing is changed by adding a conductive layer on its surface. This modifies the tubing's electrical properties from insulating to conductive, enabling electrostatic charge dissipation without altering the tubing's mechanical or fluid transport functions, thus maintaining simplicity.
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
Reduces the risk of electrostatic discharge damage while maintaining cleanliness of the polishing process by providing a safe discharge path for static electricity, thus protecting components and preventing substrate contamination.
Implementation Method 1
the conductive wrapper configured to flow an electrostatic discharge
Implementation Method 2
the conductive wire configured to conduct the electrostatic discharge from the conductive wrapper to a grounding source
Data Source
AI summary
A polishing assembly includes a chemical mechanical polishing system, a fluid source, and a fluid delivery conduit to carry a fluid from the fluid source into the chemical mechanical polishing system. The chemical mechanical polishing system including a platen to support a polishing pad, a carrier head to support a substrate and bring the substrate into contact with the polishing pad, and a motor to cause relative motion between platen and the carrier head. The fluid delivery conduit includes electrically insulative tubing, a conductive wrapper wrapped around an outer diameter of the tubing from a first end of the tubing to a second end of the tubing, and a conductive wire attached to the conductive wrapper first end. The conductive wrapper is configured to conduct an electrostatic discharge, and the conductive wire is configured to conduct the electrostatic discharge from the conductive wrapper to a grounding source.