PVD Shield Ceramic Insulation RF Bias Isolation
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Solution Overview
Problem
In plasma-based technologies, applying RF bias to a substrate can lead to arcing and the formation of unwanted plasmas due to the close proximity of the shield and substrate, resulting in loss of RF power and potential damage to the substrate surface.
Innovation Solution
A shield with a ceramic insulation material is used, maintaining a gap of less than 2 mm between the shield and substrate, and connected to ground through a low-pass filter to prevent high-frequency RF power loss and allow DC signal dissipation, thereby isolating the RF bias to the site-specific region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the shield is located close to the substrate surface to define the site isolated region, then the site isolated region is well defined and regions do not interact, but arcing or unwanted plasma formation occurs between the shield and substrate
Solution Approach 1:
An insulating material is introduced as an intermediary between the conductive shield and the substrate. This intermediary prevents direct electrical contact and eliminates the harmful arcing and unwanted plasma formation, while allowing the shield to remain in close proximity to the substrate for precise site isolation definition.
2Manufacturing precision
If the shield is located close to the substrate surface, then the site isolated region is well defined, but RF power is lost and substrate surface damage may occur
Solution Approach 1:
The insulating material acts as a mediator that prevents RF power leakage from the substrate to the grounded shield. By blocking the unwanted electrical pathway, RF power is retained for its intended purpose of affecting the RF/DC bias effect in the site isolated region, eliminating power loss while maintaining close shield-substrate positioning for precise region definition.
3Adaptability or versatility
If a shield is used to define site isolated regions, then processing can be performed on specific substrate regions, but the close proximity to substrate may cause damage
Solution Approach 1:
The insulating material serves as a protective intermediary layer between the shield and substrate. It enables the shield to be positioned close to the substrate for versatile site-specific processing while simultaneously preventing direct contact that would cause substrate surface damage, thus protecting the substrate during localized processing operations.
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 effectively suppresses arcing and unwanted plasmas, ensuring the intended RF/DC bias effect is maintained, protecting the substrate surface and enhancing the efficiency of RF power utilization.
Implementation Method 1
The shield may be directly connected to ground, or may further be connected to ground through a low-pass filter operable to prevent the loss of high frequency RF power through the shield to ground but allow the dissipation of charge from the shield to ground through a low frequency or DC signal
Implementation Method 2
A shield with a ceramic insulation material is used, maintaining a gap of less than 2 mm between the shield and substrate
Data Source
AI summary
In some embodiments of the present invention, a shield is provided wherein the shield comprises a ceramic insulation material. The ceramic insulation material fills the space between the shield and the substrate surface and maintains a gap of less than about 2 mm and advantageously, less than about 1 mm. The shield may further be connected to ground through a low-pass filter operable to prevent the loss of high frequency RF power through the shield to ground but allow the dissipation of charge from the shield to ground through a low frequency or DC signal. In some embodiments, the ceramic insulating material further comprises a removable ceramic insert. The ceramic insert may be used to select the size of the aperture. The ceramic insert further comprises a slot operable to isolate the bottom lip of the ceramic insert from the upper portion for a PVD deposition.