Semiconductor Process Chamber Wall Protection for Clean Etching
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Solution Overview
Problem
Current dry development methods for metal oxide resists in semiconductor manufacturing face challenges with the incomplete removal of reaction by-products from process chamber walls, leading to contamination and reduced process stability.
Innovation Solution
A method involving the formation of a protective layer on chamber walls using plasma deposition, followed by an etch process with HBr gas, and subsequent removal of residues using an oxidizing plasma, effectively preventing contamination and maintaining chamber integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If dry development process is used to avoid structural integrity loss, then structural integrity is improved, but incomplete removal of reaction by-products occurs leading to contamination
Solution Approach 1:
A fluorocarbon protective layer is deposited on the chamber walls to act as an intermediary barrier. This layer prevents direct contact between reaction by-products and the chamber wall surface, allowing complete removal of by-products without compromising structural integrity. The protective layer mediates between the etch process and chamber walls, enabling thorough cleaning while maintaining structural soundness.
Solution Approach 2:
The chamber wall surface properties are changed by depositing a fluorocarbon protective layer with different chemical and physical characteristics. This parameter change allows the surface to resist adhesion of reaction by-products and enables complete removal through plasma cleaning, resolving the contradiction between maintaining structural integrity and preventing contamination.
2Object-affected harmful factors
If protective layer is deposited on chamber walls, then contamination is prevented, but additional cleaning process time is required
Solution Approach 1:
The mechanical/chemical cleaning process is replaced with a plasma-based cleaning process. Instead of using lengthy chemical etchants or mechanical scraping to remove the protective layer, a fluorocarbon-selective plasma cleaning process is used that rapidly removes the protective layer without affecting the chamber wall structure, significantly reducing cleaning time.
Solution Approach 2:
The cleaning process parameters are changed from chemical/ mechanical methods to plasma-based methods. This parameter change enables selective removal of the fluorocarbon protective layer through plasma chemistry, achieving complete removal in a time-efficient manner while preserving the chamber wall integrity.
3Quantity of substance
If wet development is used for complete removal of photoresist, then removal completeness is improved, but structural integrity is lost due to capillary forces
Solution Approach 1:
The wet chemical development process is replaced with a dry plasma-based development process. This substitution eliminates the capillary forces associated with liquid solvent removal while maintaining complete removal of photoresist through plasma chemistry, thereby preserving structural integrity.
Solution Approach 2:
The development process parameters are changed from liquid-based chemical development to gas-phase plasma development. This parameter change eliminates the harmful capillary forces of liquid removal while achieving complete photoresist removal through controlled plasma reactions, resolving the contradiction between removal completeness and structural integrity.
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 method ensures efficient removal of etch by-products, maintaining chamber health and stability, and reducing the need for lengthy cleaning processes, thereby enhancing process throughput and effectiveness.
Implementation Method 1
igniting a first plasma including the fluorogas, the first plasma depositing a protective layer over inner surfaces of the process chamber
Implementation Method 2
igniting a second plasma including the oxidizing gas, the second plasma removing the protective layer
Data Source
AI summary
A method for performing an etch process includes forming a first protective layer over chamber walls of a semiconductor process chamber and performing a first etch process on an exposed major surface of a first substrate loaded into the semiconductor process chamber. The exposed major surface includes a first metal oxide resist layer. After performing the first etch process on the first substrate, the first protective layer is removed from the chamber walls with a cleaning process.