Plasma Chamber Edge Ring Cleaning for Stable Gap Region Plasma
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Solution Overview
Problem
Undesired processing byproducts accumulate in the gap between the peripheral edge of the substrate and the inward-facing portions of the edge ring in electrostatic chucks, leading to plasma instabilities, arcing, and surface defectivity, which reduces device yield and increases chamber contamination and downtime.
Innovation Solution
A plasma processing system that uses pulsed voltage waveforms and an edge tuning circuit to control plasma uniformity and ion energy distribution, allowing targeted cleaning of the gap region between the substrate and edge ring while protecting the substrate-supporting surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional chamber cleaning methods are used to clean the gap region, then processing byproducts are removed, but system availability decreases and production capacity is reduced due to increased downtime
Solution Approach 1:
The patent applies preliminary action by performing in-situ cleaning of the gap region during the substrate processing cycle itself, rather than waiting for separate chamber cleaning operations. The edge ring structure with its inwardly disposed surface positioned within the substrate edge region allows cleaning plasma to be generated and applied directly to the gap area during normal processing, removing processing byproducts before they can cause arcing or contamination without requiring system shutdown
Solution Approach 2:
The edge ring structure enables the gap region to clean itself through in-situ plasma generation. The inwardly disposed surface of the edge ring acts as a plasma-generating surface that produces cleaning plasma directly at the gap region during substrate processing. This self-service mechanism continuously removes processing byproducts from the gap area without external intervention or system downtime, maintaining cleanliness autonomously throughout operation
2Reliability
If frequent chamber cleaning is performed to remove processing byproducts from the gap, then arcing and surface defectivity are reduced, but chamber component damage increases and useful lifetime decreases
Solution Approach 1:
The patent applies local quality by creating a specialized edge ring structure with an inwardly disposed surface specifically positioned within the substrate edge region to generate cleaning plasma locally at the gap area. This localized plasma generation targets only the gap region where processing byproducts accumulate, rather than exposing entire chamber components to aggressive cleaning plasma. The edge ring structure concentrates the cleaning effect precisely where needed while leaving other chamber surfaces unaffected, thus maintaining plasma stability without causing widespread component damage
Solution Approach 2:
The edge ring structure serves as an intermediary element between the substrate and the chamber wall, with its inwardly disposed surface acting as a plasma-generating interface. This intermediary structure generates cleaning plasma that targets processing byproducts in the gap region without requiring direct exposure of the substrate or other sensitive chamber components to aggressive cleaning conditions. The edge ring mediates the cleaning process, protecting other chamber components from damage while effectively removing contaminants from the critical gap area
3Productivity
If processing byproducts accumulate in the gap region, then chamber cleaning frequency can be reduced, but plasma instabilities and arcing increase causing surface defectivity
Solution Approach 1:
The patent applies continuity of useful action by implementing continuous in-situ cleaning of the gap region during substrate processing operations. The edge ring structure with its inwardly disposed surface generates cleaning plasma continuously throughout the processing cycle, maintaining the gap region free of processing byproducts in real-time. This continuous cleaning action prevents byproduct accumulation that would otherwise lead to plasma instabilities and arcing, ensuring plasma stability is maintained throughout uninterrupted production operations without requiring periodic shutdowns for cleaning
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 system effectively removes processing byproducts from the gap region, reducing plasma instabilities and surface damage, thereby enhancing device yield and reducing chamber downtime.
Implementation Method 1
generating a plasma in a processing region defined by a chamber lid and a substrate support assembly
Implementation Method 2
establishing a pulsed voltage waveform at the edge control electrode that is different from the first pulsed voltage waveform
Data Source
AI summary
Embodiments provided herein generally include plasma processing systems configured to preferentially clean desired surfaces of a substrate support assembly by manipulating one or more characteristics of an in-situ plasma and related methods. In one embodiment, a plasma processing method includes generating a plasma in a processing region defined by a chamber lid and a substrate support assembly, exposing an edge ring and a substrate supporting surface to the plasma, and establishing a pulsed voltage (PV) waveform at the edge control electrode.