Halogen Removal via UV and Ozone in Semiconductor Degas Chamber
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Solution Overview
Problem
The existing methods for removing halogen residues from semiconductor wafers during processing, such as downstream strippers, either decrease wafer processing throughput or require high temperatures that can damage certain materials, leading to contamination issues like self-contamination, cross-contamination, and equipment contamination.
Innovation Solution
A method involving a degas chamber where wafers are treated with UV light and a gas mixture of ozone, oxygen, or H2O to remove halogen residues, maintaining a vacuum and avoiding high temperatures, thereby preventing contamination without reducing processing throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a downstream stripper module is used to remove halogen residues, then halogen removal effectiveness is improved, but wafer processing throughput decreases
Solution Approach 1:
The patent extracts the halogen removal function from the vacuum processing tool by using a separate load lock chamber. The load lock chamber is vented to atmosphere, allowing the use of atmosphere-based plasma or chemical methods for halogen removal without compromising the vacuum environment needed for semiconductor processing. This separation enables the main processing tool to maintain high throughput while the load lock handles halogen removal.
Solution Approach 2:
The load lock chamber serves as an intermediary between the vacuum processing environment and the atmosphere-based halogen removal process. By transferring wafers through this intermediate chamber, the system enables effective halogen removal using atmosphere plasma or chemicals without requiring the main processing chambers to be dedicated to stripping functions.
2Manufacturing precision
If high temperature processing is used to remove halogen residues, then halogen removal effectiveness is improved, but material damage and contamination increase
Solution Approach 1:
The patent changes the temperature parameter by performing halogen removal at low temperatures using atmosphere plasma or chemical treatments in the load lock chamber. This avoids the high temperatures (typically >400°C) that would cause material damage or contamination, while still achieving effective halogen removal through alternative mechanisms such as plasma chemistry or low-temperature reactions.
Solution Approach 2:
The patent employs strong oxidants such as ozone or oxygen plasma in the atmosphere load lock chamber to rapidly remove halogen residues at low temperatures. These strong oxidizing agents can effectively convert and remove halogen contaminants without requiring high thermal energy, thus avoiding material damage while achieving thorough halogen removal.
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
Effectively reduces halogen residues without the need for high-temperature downstream strippers, preventing contamination and increasing wafer processing throughput by allowing additional processing chambers in the tool.
Implementation Method 1
The processed wafer is treated in the degas chamber with UV light and a flow of gas comprising at least one of ozone, oxygen, or H2O
Implementation Method 2
The processed wafer is treated in the degas chamber with UV light and a flow of gas comprising at least one of ozone, oxygen, or H2O
Implementation Method 3
The processed wafer is transferred into a degas chamber, wherein a vacuum is maintained in the degas chamber
Data Source
AI summary
A wafer is provided into an entrance load lock chamber. A vacuum is created in the entrance load lock chamber. The wafer is transported to a processing tool. The wafer is processed in a process chamber to provide a processed wafer, wherein the processing forms halogen residue. A degas step is provided in the process chamber after processing the wafer. The processed wafer is transferred into a degas chamber. The processed wafer is treated in the degas chamber with UV light and a flow of gas comprising at least one of ozone, oxygen, or H2O. The flow of gas is stopped. The UV light is stopped. The processed wafer is removed from the degas chamber.