Electrostatic Chuck Feed Terminal Layout to Prevent Discharge
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Discharge is likely to occur at the feed terminal of an electrostatic chuck due to low ambient air pressure, which can compromise the operation of the chuck.
Innovation Solution
The electrostatic chuck is designed with a bypass portion that electrically connects the feed terminal and internal electrode without overlapping them in a top view, allowing the feed terminal to be positioned away from discharge-prone areas, thereby preventing discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the feed terminal is arranged in a position overlapped with the internal electrode in top view, then the electrical connection is simplified, but discharge is likely to occur due to low ambient air pressure
Solution Approach 1:
The patent transitions from a two-dimensional overlapping arrangement (top view) to a three-dimensional non-overlapping arrangement by introducing a bypass portion that routes the electrical connection through the thickness direction of the dielectric substrate. This allows the feed terminal and internal electrode to be positioned at different heights, eliminating the discharge risk associated with horizontal overlap while maintaining electrical connectivity.
Solution Approach 2:
The bypass portion acts as an intermediary element that provides an alternative electrical connection path between the feed terminal and internal electrode. This intermediary structure avoids the harmful discharge zone by routing electricity through a different spatial path, thereby preventing discharge while maintaining the necessary electrical connection.
2Reliability
If the feed terminal is positioned away from the internal electrode to prevent discharge, then discharge is prevented, but the arrangement flexibility is reduced
Solution Approach 1:
By utilizing the thickness dimension of the dielectric substrate, the patent creates additional arrangement flexibility. The bypass portion can be routed through the substrate thickness, allowing the feed terminal to be positioned anywhere on the outer surface while maintaining connection to the internal electrode, thus preserving arrangement flexibility without compromising discharge prevention.
3Ease of manufacture
If the feed terminal is arranged in the second part (rim portion), then the connection to internal electrode is direct, but discharge is likely due to low air pressure in that region
Solution Approach 1:
The bypass portion serves as an intermediary that allows the feed terminal to be positioned in the second part for manufacturing convenience while preventing direct exposure to the low-pressure discharge zone. The intermediary structure routes the electrical connection through a path that avoids the harmful environmental conditions in the rim portion.
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
This configuration prevents discharge at the feed terminal, ensuring reliable operation and reducing the risk of electrical failures.
Implementation Method 1
When a voltage is applied to the attraction electrode, an electrostatic force is generated, and the wafer placed on the dielectric substrate is attracted and held
Implementation Method 2
The internal electrode may be provided as an 'RF electrode' configured to generate plasma to be pulled towards the wafer
Data Source
AI summary
An electrostatic chuck 10 includes a dielectric substrate 100 which includes a first part 101 including a placement surface and a second part 102 which protrudes from an outer circumferential edge of the first part 101 further towards an outer circumferential side, an internal electrode 140 provided inside the second part 102, a feed terminal 160 provided in a position which is not overlapped with the internal electrode 140 in top view, and a bypass portion 150 which is provided inside the dielectric substrate 100 and electrically connects the feed terminal 160 and the internal electrode 140.