PECVD Chamber Cleaning Using Oxidation and Fluorine Radicals
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Solution Overview
Problem
Existing PECVD chamber cleaning methods are inefficient, leading to prolonged cleaning times, ion damage to chamber surfaces, and residual carbon-based by-products, which reduce productive time and increase costs and environmental impact.
Innovation Solution
A method involving a first plasma generated within the PECVD chamber using an oxygen-containing component to oxidize depositions, followed by a second plasma from a remote plasma source containing fluorine radicals, which are introduced into the chamber along with an additional oxygen-containing component to effectively remove the modified depositions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a remote plasma source is used to produce high radical concentration with low ion density for cleaning, then ion damage to chamber surfaces is reduced, but system complexity and cost increase
Solution Approach 1:
The patent introduces an intermediary substance (fluorinated cleaning agent) that mediates the cleaning process. The cleaning agent is activated by a plasma field to generate fluorine radicals in-situ within the chamber, eliminating the need for a remote plasma source while still achieving low ion damage cleaning. The fluorinated compound serves as a mediator that converts plasma energy into selective radical generation at the deposition sites.
Solution Approach 2:
The patent extracts the harmful ion component from the plasma cleaning process by using a fluorinated cleaning agent that selectively generates fluorine radicals through plasma activation. The cleaning function is separated from the ion bombardment function, allowing radical-based cleaning without the damaging ion flux that would otherwise be present in direct plasma cleaning.
2Reliability
If traditional plasma cleaning methods are used to remove depositions, then cleaning effectiveness is achieved, but ion damage roughens chamber surfaces over time
Solution Approach 1:
The patent changes the chemical parameters of the cleaning process by introducing fluorinated cleaning agents with specific molecular structures. These compounds are designed to decompose preferentially at deposition sites under plasma activation, changing the cleaning mechanism from physical ion bombardment to chemical reaction-based removal. The parameter change involves using compounds with C-F bonds that have specific activation energies and reaction pathways.
Solution Approach 2:
The patent converts the harmful effect of plasma into a beneficial cleaning mechanism. Instead of using plasma ions directly to remove depositions (which causes damage), the plasma field is used to activate fluorinated cleaning agents that then chemically react with and remove depositions. The harmful plasma ion flux is transformed into a useful radical generation source for selective chemical cleaning.
3Manufacturing precision
If cleaning cycles are performed frequently to maintain chamber cleanliness, then particulate contamination is reduced, but productive time is lost
Solution Approach 1:
The patent enables continuous cleaning action during the deposition process itself. The fluorinated cleaning agents are introduced continuously or periodically during deposition, allowing simultaneous deposition and cleaning to occur. This eliminates the need for separate cleaning cycles, as the cleaning action is integrated into the productive deposition time, maintaining continuous useful action without interrupting production.
Solution Approach 2:
The patent applies preliminary cleaning action by introducing fluorinated cleaning agents during the deposition process to prevent deposition buildup rather than removing it afterward. The cleaning agents are present from the beginning of deposition, preventing particulate formation in the first place, which eliminates the need for subsequent cleaning cycles and maximizes productive time.
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
This approach significantly reduces chamber cleaning time, minimizes ion damage, and effectively removes residual carbon-based by-products, thereby maximizing productive time, reducing gas consumption, and maintaining film quality and substrate uniformity.
Implementation Method 1
a first plasma is generated in the chamber from the first cleaning gas mixture in a first cleaning step
Implementation Method 2
generating a first plasma in the chamber from the first cleaning gas mixture in a first cleaning step
Implementation Method 3
generating a second plasma in the remote plasma source from a second cleaning gas mixture in a remote plasma generating step, wherein the second plasma comprises fluorine radicals
Implementation Method 4
performing a second cleaning step by allowing fluorine radicals from the second plasma to enter the chamber
Data Source
AI summary
A method of cleaning a chamber of a plasma processing device to remove depositions formed after the plasma processing device has been used to deposit a dielectric material including silicon and carbon by introducing a first cleaning gas mixture into the chamber through a first gas inlet in a first introducing step; generating a first plasma in the chamber from the first cleaning gas mixture in a first cleaning step; introducing a second cleaning gas mixture into a remote plasma source in a second introducing step; generating a second plasma in the remote plasma source from a second cleaning gas mixture in a remote plasma generating step; and performing a second cleaning step by allowing fluorine radicals from the second plasma to enter the chamber and introducing a third cleaning gas mixture into the chamber at the same time as the fluorine radicals from the second plasma.