Contoured Ceiling Electrode for Uniform Substrate Cleaning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional substrate cleaning chambers fail to uniformly clean ever smaller features on substrates, leading to void formation and increased electrical resistance, and are prone to residue buildup that can contaminate the substrate and chamber surfaces, requiring frequent disassembly and cleaning.
Innovation Solution
A cleaning chamber with a contoured ceiling electrode and dielectric ring that varies plasma density across the substrate surface using dual frequency electrical power, along with a conditioning layer to delay chamber cleaning and extend processing cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional pre-clean chambers use uniform cleaning processes, then the process is simple to operate, but the cleaning uniformity across substrate features deteriorates
Solution Approach 1:
The patent applies local quality by varying the gap distance between the ceiling electrode and substrate support at different radial positions. The gap is smaller at the center and larger at the periphery, creating different plasma densities in different regions to achieve uniform cleaning across the substrate surface.
Solution Approach 2:
The patent implements dynamics by making the ceiling electrode contoured with a specific profile that changes the electric field distribution dynamically across the substrate surface. This contoured design allows the system to adapt the plasma generation characteristics to compensate for natural plasma density variations.
2Productivity
If conventional chambers accumulate process residues, then the chamber can operate for longer periods, but the residues flake off and contaminate substrates
Solution Approach 1:
The patent introduces a conditioning layer as an intermediary between the substrate and the accumulated process residues. This conditioning layer, deposited from a conditioner substrate, prevents direct adhesion of residues to chamber surfaces and eliminates the flaking problem while allowing extended operational cycles.
Solution Approach 2:
The patent converts the harmful effect of accumulated residues by using them as a source material for the conditioning layer. The residues that would normally flake off and contaminate substrates are instead utilized to form a protective conditioning layer on conditioner substrates, which then prevent contamination when transferred to the processing chamber.
3Object-affected harmful factors
If conventional chambers use process kits to receive residues, then the chamber can handle deposits, but frequent disassembly and cleaning reduce productivity
Solution Approach 1:
The patent implements self-service by enabling the chamber components to automatically receive and contain process residues through the conditioning layer mechanism. The conditioner substrates selflessly accumulate residues that would otherwise harm the system, eliminating the need for manual intervention and frequent disassembly for cleaning.
Solution Approach 2:
The patent applies preliminary action by depositing the conditioning layer on conditioner substrates before they are placed in the chamber to receive process residues. This pre-preparation ensures that the substrates are ready to immediately begin capturing residues, preventing contamination issues before they arise and reducing the frequency of maintenance operations.
4Device complexity
If metal-containing residues accumulate on the ceiling with external inductor coils, then the chamber structure is simple, but the residues reduce induction energy coupling
Solution Approach 1:
The patent extracts the inductor coil from its conventional position on the chamber ceiling and relocates it to the substrate support structure. This extraction removes the source of residue accumulation from the ceiling, preventing the formation of insulating layers that would degrade induction energy coupling while maintaining the simplicity of the overall system.
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
Achieves uniform etch cleaning across the substrate surface and extends the number of processing cycles before chamber maintenance by preventing residue flaking and maintaining chamber cleanliness.
Implementation Method 1
allowing a plasma density of a plasma formed between the arcuate surface and the substrate support to vary radially across the substrate support
Implementation Method 2
a gas energizer to energize the cleaning gas to etch away the surface of the features to clean the substrate
Data Source
AI summary
A substrate cleaning chamber includes a contoured ceiling electrode having an arcuate surface that faces a substrate support and has a variable cross-sectional thickness to vary the gap size between the arcuate surface and the substrate support to provide a varying plasma density across the substrate support. A dielectric ring for the cleaning chamber comprises a base, a ridge, and a radially inward ledge that covers the peripheral lip of the substrate support. A base shield comprises a circular disc having at least one perimeter wall. Cleaning and conditioning processes for the cleaning chamber are also described.