USG Passivation Layer for TEOS Accumulation in Process Chambers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current semiconductor processing technologies face limitations in extending the accumulation limit of TEOS-based films within process chambers without compromising film uniformity and increasing the risk of particle defects and tool component degradation, particularly due to the high cost and operational challenges of temperature-controlled showerheads.
Innovation Solution
Implementing an in-situ passivation method using undoped-silicate glass (USG) films periodically deposited during TEOS depositions to create a barrier that reduces film shedding from chamber components, thereby extending the accumulation limit and maintaining film quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If RFTC showerheads are used to increase TEOS accumulation limit, then accumulation limit increases to 16-18 μm, but device complexity increases due to temperature control capability and RF-filtering circuitry
Solution Approach 1:
The patent uses a disposable sacrificial layer deposited on the showerhead that can be easily removed after serving its purpose of enabling higher TEOS accumulation. This avoids the need for complex permanent temperature control systems while achieving the same accumulation limit extension.
Solution Approach 2:
The patent changes the chemical composition parameter by introducing a fluorocarbon-based sacrificial layer with different properties than the TEOS dielectric layer. This parameter change allows the sacrificial layer to be selectively removed while preserving the TEOS accumulation, extending the effective accumulation limit without complex hardware.
2Strength
If RFTC showerheads operate at higher temperature to produce compressive film, then film adhesion improves, but tool component lifetime decreases due to accelerated AlF3 growth and process shifts
Solution Approach 1:
The patent applies a preliminary sacrificial layer before TEOS deposition that pre-establishes the necessary adhesion properties. This allows subsequent TEOS layers to accumulate without requiring high-temperature processing, thereby preserving tool component lifetime while maintaining film adhesion.
Solution Approach 2:
The fluorocarbon-based sacrificial layer acts as an intermediary between the showerhead surface and the TEOS dielectric accumulation. This intermediary provides the necessary adhesion promotion without requiring the TEOS process itself to operate at elevated temperatures, thus protecting tool components.
3Manufacturing precision
If plasma clean is performed frequently to maintain chamber baseline state, then film uniformity and repeatability are maintained, but productivity decreases due to loss of deposition time
Solution Approach 1:
The patent segments the deposition process into distinct phases: accumulation phase where multiple substrates are processed without cleaning, and restoration phase where a single substrate is processed to remove the sacrificial layer. This segmentation allows extended productive accumulation periods while maintaining precision through periodic restoration.
Solution Approach 2:
The patent implements periodic action by alternating between extended accumulation cycles and periodic restoration cycles. During accumulation cycles, productivity is maximized by processing multiple substrates without cleaning. Periodic restoration cycles maintain film uniformity by removing the sacrificial layer, creating a rhythm that balances productivity and precision.
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 USG passivation layer effectively increases the TEOS accumulation limit by 9 μm or more, reducing particle defects and extending tool lifespan while maintaining film uniformity and quality, thus enhancing process throughput and reducing the need for frequent plasma cleans.
Implementation Method 1
forming an undoped-silicate glass (USG) film on the components internal to the process chamber to passivate accumulated levels of the dielectric film layers
Implementation Method 2
the chamber is subjected to a plasma clean. The plasma clean is needed to reset conditions of the chamber to a baseline state
Data Source
AI summary
The disclosed subject matter is a method to reduce film shedding from components internal to a process chamber. In one example, the method includes forming a dielectric film layer on each of a successive plurality of substrates within the process chamber, and, after a pre-determined number of the successive plurality of substrates have had the dielectric film layers formed thereon, forming an undoped-silicate glass (USG) film on the components internal to the process chamber to passivate accumulated levels of the dielectric film layers. Other devices and methods are disclosed.