Electrostatic Chuck Through-Hole Shielding Against Abnormal Discharge
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Solution Overview
Problem
Existing plasma processing apparatuses experience abnormal discharge in through-holes of electrostatic chucks, which affects the reliability and efficiency of the plasma processing operation.
Innovation Solution
Incorporating a conductive structure that surrounds the through-holes and extends upward from the level of or above the bias electrode, reducing the potential difference and preventing abnormal discharge by adhering to the breakdown voltage defined by Paschen's Law.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a through-hole is provided in the electrostatic chuck for heat transfer gas supply, then heat transfer efficiency is improved, but abnormal discharge occurs in the through-hole
Solution Approach 1:
A conductive structure is introduced as an intermediary element within the through-hole to modify the electrical field distribution. This conductive structure acts as a mediator between the plasma environment and the electrostatic chuck, preventing direct discharge paths while maintaining gas flow channels for heat transfer.
Solution Approach 2:
The conductive structure is positioned specifically at the lower portion of the through-hole where discharge is most likely to occur. This localized modification addresses the discharge problem at the critical location without affecting the overall heat transfer function of the through-hole.
2Reliability
If the conductive structure extends higher in the through-hole, then abnormal discharge is reduced, but device complexity increases
Solution Approach 1:
The conductive structure extends partially into the through-hole rather than fully blocking it. The extension height is optimized to provide sufficient discharge prevention while maintaining gas flow pathways, avoiding excessive action that would completely obstruct the through-hole and increase complexity unnecessarily.
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 solution effectively prevents or reduces abnormal discharge in the through-holes, ensuring stable plasma processing and maintaining the intended conductance for heat transfer gases, thereby enhancing the operational reliability and efficiency of the plasma processing apparatus.
Implementation Method 1
preventing abnormal discharge by adhering to the breakdown voltage defined by Paschen's Law
Implementation Method 2
an electrostatic clamp electrode inside the dielectric structure
Data Source
AI summary
A plasma processing apparatus includes a plasma processing chamber, a base in the plasma processing chamber, and an electrostatic chuck on the base. The electrostatic chuck includes a dielectric structure having a substrate support surface and a ring support surface, an electrostatic clamp electrode inside the dielectric structure, a bias electrode inside the dielectric structure and below the electrostatic clamp electrode, and at least one conductive structure at least partially located inside the dielectric structure. The dielectric structure has a through-hole extending through the dielectric structure from the substrate support surface or the ring support surface to a lower surface of the dielectric structure. The at least one conductive structure surrounds the through-hole and extends upward from a same level as the bias electrode in a height direction or from a higher level than the bias electrode.