PECVD Chamber Cleaning for SiCN Deposits Using Remote Fluorine Radicals
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Solution Overview
Problem
Existing PECVD chamber cleaning methods are inefficient, particularly when dealing with dielectric materials like SiCN and SiC, as they require prolonged cleaning times, lead to ion damage, and result in residual carbon-based by-products.
Innovation Solution
A method involving a two-step cleaning process: first, a plasma is generated within the chamber using an oxygen-containing component to oxidize the depositions, followed by the introduction of fluorine radicals from a remote plasma source, along with an additional oxygen-containing component, to effectively remove the modified depositions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a plasma is generated within the chamber using an oxygen-containing component to oxidize the depositions, then the deposits are modified for easier removal, but ion damage to chamber surfaces occurs and cleaning time is prolonged
Solution Approach 1:
The cleaning process is divided into two distinct stages: first, an oxygen-containing plasma is generated within the chamber to oxidize and modify the carbon-rich deposits, making them more removable; second, fluorine radicals from a remote plasma source are introduced to etch and remove the oxidized deposits. This segmentation allows each stage to be optimized independently, achieving complete removal while minimizing ion damage.
Solution Approach 2:
The oxygen-containing plasma acts as an intermediary that transforms the carbon-rich deposits into oxidized species that are more susceptible to fluorine radical etching. This intermediate oxidation step enables the fluorine radicals to effectively remove the deposits without requiring prolonged exposure that would cause ion damage to chamber surfaces.
2Manufacturing precision
If fluorine radicals from a remote plasma source are introduced to remove carbon-based deposits, then complete removal is achieved, but cleaning time increases and system complexity increases
Solution Approach 1:
The oxygen-containing plasma is applied in advance to oxidize the carbon-rich deposits, transforming them into a form that is much more readily removed by fluorine radicals. This preliminary oxidation action significantly reduces the subsequent fluorine radical exposure time required for complete deposit removal, thereby reducing total cleaning time.
Solution Approach 2:
The invention changes the chemical state of the deposits from carbon-rich to oxidized through the first plasma treatment, which fundamentally alters their reactivity toward fluorine radicals. This parameter change enables rapid and complete removal of carbon-based deposits by fluorine radicals within a shorter time frame.
3Manufacturing precision
If cleaning is performed after each substrate to maintain film quality, then substrate uniformity is maintained, but productive time is reduced
Solution Approach 1:
The cleaning process is designed to be highly efficient and targeted, removing only the necessary deposits through the two-stage process. The fluorine radical remote plasma source continuously provides reactive species that effectively etch oxidized deposits, maintaining clean chamber conditions without requiring extended cleaning cycles that would reduce 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 ensures complete removal of deposits, thereby maximizing productive time and maintaining film quality and substrate uniformity.
Implementation Method 1
The fabrication of devices such as semiconductor devices frequently involves the deposition of films such as dielectric films including silicon oxides, SiN, SiC, SiOC and SiCN... which utilizes a plasma to break down precursors in a chamber containing a substrate for deposition
Implementation Method 2
introducing a first cleaning gas mixture into the chamber through a first gas inlet in a first introducing step, the first cleaning gas mixture comprising a first oxygen-containing component; generating a first plasma in the chamber from the first cleaning gas mixture in a first cleaning step
Implementation Method 3
PECVD deposited dielectrics such as silicon oxides, SiN and SiOC can be readily etched with fluorine radicals F* from disassociated NF3... introducing a second cleaning gas mixture into a remote plasma source in a second introducing step, wherein the second cleaning gas mixture comprises a fluorine-containing component; 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
Data Source
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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 comprising silicon and carbon is provided, the method comprising the steps of: • introducing a first cleaning gas mixture into the chamber through a first gas inlet in a first introducing step, the first cleaning gas mixture comprising a first oxygen-containing component; • 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, wherein the second cleaning gas mixture comprises a fluorine-containing component; • 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; 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, wherein the third cleaning gas mixture comprises a second oxygen-containing component. A plasma processing device comprising: • a chamber; • a plasma generating means configured, in use, to generate a plasma within the chamber; • at least one gas inlet; • a remote plasma source configured, in use, to generate a plasma; • a connector connecting the remote plasma source to the chamber, and • a controller.