In-Situ Plasma Chamber Cleaning via Sequential Gas Injection
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Solution Overview
Problem
Plasma processing chambers used in semiconductor device fabrication accumulate metal-containing etching by-products, which lead to contamination, process control issues, and substrate defects due to the buildup of residuals during the etching process, necessitating an effective cleaning method to maintain chamber integrity and performance.
Innovation Solution
An in-situ dry cleaning process involving sequential supply of boron-containing, halogen-containing, and oxygen-containing gases into the plasma processing chamber in the absence of a substrate to efficiently remove metal and carbon-based contaminants without damaging chamber components, utilizing specific gas combinations and controlled process parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If plasma etching process is performed to fabricate gate structure, then transistor devices are formed on substrate, but metal-containing etching by-products accumulate on chamber surfaces and substrate
Solution Approach 1:
The cleaning process is divided into three distinct sequential steps, each using a different gas composition tailored to remove specific types of contaminants: (1) boron-containing gas for metal residuals, (2) halogen-containing gas for organic/carbon-based residuals, and (3) oxygen-containing gas for final surface oxidation and cleanup. This segmented approach allows each cleaning step to target specific contaminants effectively without interfering with chamber components.
Solution Approach 2:
The cleaning process utilizes controlled variations in gas composition, pressure, and plasma power parameters to optimize removal of different contaminant types at different stages. By adjusting these parameters sequentially through the three cleaning steps, the process efficiently removes metal-containing by-products while preventing damage to chamber surfaces and maintaining etching performance.
2Reliability
If cleaning is performed to remove metal-containing by-products, then chamber contamination is reduced, but process time and complexity increase
Solution Approach 1:
The cleaning process is designed as a continuous in-situ operation performed without breaking vacuum or removing the substrate, allowing cleaning to occur immediately after etching while the chamber is still under vacuum. This continuous approach eliminates the need for chamber venting, substrate removal, and re-loading, significantly reducing total cleaning time while maintaining high reliability through consistent contaminant removal.
Solution Approach 2:
The cleaning process uses plasma chemistry reactions where the cleaning gases react with and volatilize contaminants, which are then pumped away by the existing vacuum system. The process leverages the chamber's own vacuum infrastructure and plasma generation capability, eliminating the need for additional cleaning equipment or manual intervention, thereby reducing both time and operational complexity.
3Object-generated harmful factors
If aggressive cleaning methods are used to remove accumulated by-products, then chamber surfaces are cleaned, but chamber components may be damaged
Solution Approach 1:
Each cleaning gas is selected and optimized to target specific types of contaminants on specific chamber surfaces: boron-containing gas for metal residuals on hard surfaces, halogen-containing gas for organic contaminants, and oxygen-containing gas for final surface treatment. This localized approach ensures effective contaminant removal while using gentler chemistry appropriate for each surface type, preventing damage to chamber components.
Solution Approach 2:
The cleaning process carefully controls plasma power, pressure, and gas flow parameters at each stage to balance cleaning effectiveness with component protection. By adjusting these parameters sequentially through the three cleaning steps, the process achieves thorough contaminant removal while maintaining chamber component integrity through controlled, progressive cleaning rather than aggressive single-step 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 method effectively cleans the plasma processing chamber, preventing residual contamination and maintaining chamber integrity, ensuring high-quality semiconductor device fabrication by removing metal and carbon-based residues, thereby enhancing etching performance and reducing substrate defects.
Implementation Method 1
supplying a first cleaning gas including at least a boron containing gas into a processing chamber in absence of a substrate disposed therein
Implementation Method 2
supplying a second cleaning gas including at least a halogen containing gas into the processing chamber in absence of the substrate
Implementation Method 3
supplying a third cleaning gas including at least an oxygen containing gas into the processing chamber in absence of the substrate
Implementation Method 4
Methods for in-situ chamber dry clean utilized in an etching processing chamber
Data Source
AI summary
Embodiments of the invention include methods for in-situ chamber dry cleaning a plasma processing chamber utilized for gate structure fabrication process in semiconductor devices. In one embodiment, a method for in-situ chamber dry clean includes supplying a first cleaning gas including at least a boron containing gas into a processing chamber in absence of a substrate disposed therein, supplying a second cleaning gas including at least a halogen containing gas into the processing chamber in absence of the substrate, and supplying a third cleaning gas including at least an oxygen containing gas into the processing chamber in absence of the substrate.