Helium Plug Design for Substrate Support Arcing Reduction
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Solution Overview
Problem
In substrate processing systems, manufacturing tolerances lead to larger channel diameters and volumes at the interface between the baseplate and ceramic layer, increasing the likelihood of plasma light-up and arcing, resulting in current spikes and bond layer erosion.
Innovation Solution
A dual porous plug is introduced, with an upper portion extending into the baseplate and a lower portion in the ceramic layer, reducing the empty volume and electric field in the gap, and the bottom surface of the ceramic layer is ground to minimize the gap width, thereby reducing arcing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If channels are formed through the baseplate and ceramic layer to provide heat transfer gas, then cooling efficiency is improved, but manufacturing tolerances cause larger channel diameters and volumes at the interface, increasing plasma light-up and arcing
Solution Approach 1:
The patent employs porous plugs made of porous material (such as porous ceramic or porous metal) inserted into the channels at the interface between the baseplate and ceramic layer. These porous plugs reduce the empty volume within the channels while maintaining gas flow pathways, thereby decreasing the likelihood of plasma light-up and arcing without compromising cooling efficiency. The porous structure allows heat transfer gas to pass through while minimizing the volume that could support plasma formation.
2Reliability
If the channel volume at the interface is reduced to minimize arcing, then reliability is improved, but heat transfer gas flow may be restricted
Solution Approach 1:
The porous plugs are designed with controlled porosity to balance two competing requirements: reducing empty channel volume to prevent arcing while maintaining sufficient open space for heat transfer gas flow. The porous structure provides numerous small pathways that allow gas to pass through effectively, ensuring that cooling performance is maintained even though the overall channel volume is reduced.
Solution Approach 2:
The plugs are constructed from composite or porous materials that combine the properties of structural integrity (to maintain plug shape and position) with high surface area and interconnected pores (to facilitate gas flow). This composite approach allows the plugs to simultaneously reduce arcing-prone empty volume while preserving adequate heat transfer gas flow pathways.
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 implementation of the dual porous plug effectively minimizes arcing and current spikes, enhancing the stability and reliability of the substrate support by reducing the electric field and empty volume in the channel.
Implementation Method 1
The heat transfer gas facilitates cooling of the substrate and/or the ceramic layer
Implementation Method 2
a plurality of channels to provide a heat transfer gas (e.g., helium) to a backside of the substrate arranged on the ceramic layer
Implementation Method 3
reducing the empty volume and electric field in the gap, and thereby reducing arcing
Implementation Method 4
manufacturing tolerances lead to larger channel diameters and volumes at the interface between the baseplate and ceramic layer, increasing the likelihood of plasma light-up and arcing
Data Source
AI summary
A substrate support includes a baseplate, a ceramic layer arranged on the baseplate, a bond layer arranged in a first gap between the baseplate and the ceramic layer, a channel formed through the baseplate, the bond layer, and the ceramic layer, and a plug arranged in the channel. The plug includes a lower portion arranged in the baseplate and an upper portion arranged in the ceramic layer. The lower portion includes a pocket and sidewalls surrounding the pocket. The upper portion extends below the ceramic layer and the first gap into the pocket, the sidewalls of the lower portion overlap the upper portion, and a second gap between the upper portion and the lower portion is located within the pocket of the lower portion below the first gap.