Parallel Filter Isolation for Vacuum Deposition Downtime Reduction
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Solution Overview
Problem
In semiconductor film deposition, clogged filters in vaporization apparatuses require shutdown and vacuum breakage for replacement, leading to significant productive tool time loss and contamination due to ambient air exposure, as existing methods necessitate breaking the vacuum to remove and replace filters.
Innovation Solution
A method and apparatus allowing flow isolation of filters from the vapor deposition system using valves, enabling a clogged filter to be replaced without breaking the vacuum, utilizing a pair of filters connected in parallel, where one filter can be isolated and replaced while the other continues to operate, reducing downtime and contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a filter is placed in the incoming process gas stream to remove particles, then particulate contamination of wafers is reduced, but the filter becomes clogged during use requiring shutdown and replacement
Solution Approach 1:
The filter system is segmented into multiple filters arranged in parallel paths, allowing one filter to be serviced while another remains active. This segmentation enables continuous operation by dividing the filtration function across multiple independent filter elements that can be individually maintained.
Solution Approach 2:
The system maintains an inert or vacuum environment in the deposition chamber during filter replacement by isolating the filter housing from the chamber. This prevents contamination of the vacuum system with ambient air, allowing filter changes without breaking the vacuum and maintaining continuous productive operation.
2Ease of repair
If the entire vaporizer is removed from the system to replace a filter, then the filter can be replaced, but the tool shutdown causes loss of productive use of tool time
Solution Approach 1:
The filter is extracted from the vaporizer assembly and placed in a separate, independently accessible housing. This extraction allows the filter to be replaced without removing the entire vaporizer from the deposition system, enabling quick filter changes while maintaining continuous tool operation and minimizing downtime.
Solution Approach 2:
A second filter is installed in standby position before the first filter becomes completely clogged. When the first filter needs replacement, the system can switch to the second filter immediately, and the first filter can be serviced during what would otherwise be productive time, eliminating downtime entirely.
3Ease of operation
If the vacuum is broken to remove and replace a filter, then the filter can be accessed and replaced, but ambient air enters the deposition chamber causing contamination and requiring extended pumping time
Solution Approach 1:
An intermediary filter housing is introduced between the vaporizer and deposition chamber. This housing can be isolated from the vacuum system using isolation valves, allowing filter replacement in atmospheric conditions while the deposition chamber maintains its vacuum. The intermediary structure acts as a barrier that prevents ambient air from contaminating the vacuum system during filter maintenance.
4Device complexity
If a single filter is used in the vaporization apparatus, then the system is simpler, but filter clogging requires complete system shutdown and vacuum breakage
Solution Approach 1:
The filtration system is segmented into multiple parallel filter paths with independent isolation valves for each filter. This segmentation allows one filter to be serviced while another remains active, enabling continuous operation. The added complexity of multiple filters is offset by the ability to maintain uninterrupted deposition processes.
Solution Approach 2:
The filter system incorporates dynamic switching capability through isolation valves that can redirect gas flow between different filter paths. This dynamic configuration allows the system to adapt to filter maintenance needs in real-time, switching from a single static filter to a flexible multi-filter arrangement that maintains continuous operation.
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 productive tool downtime and minimizes contamination by allowing continuous operation during filter replacement and maintenance, as the system can maintain vacuum integrity and prevent exposure to ambient gases, thereby enhancing productivity and reducing the time needed for tool recovery.
Implementation Method 1
One known method of reducing particulate contamination of wafers is to place a filter in the incoming process gas stream to remove particles
Implementation Method 2
Since hot vapor can condense in a cold filter, the filter must be heated
Implementation Method 3
Shutting down a film deposition tool operating under vacuum generally requires breaking the system vacuum
Implementation Method 4
A carrier gas is often introduced into the vaporization apparatus to form a gas/vapor mixture
Data Source
AI summary
This disclosure pertains to a method and apparatus to permit changing a filter on the input line to a vacuum deposition chamber without breaking or reducing the vacuum for the deposition chamber and other components in the deposition system. Isolation valves are provided at the inlet and outlet of the filter so the filter can be isolated from the source of vacuum and the deposition chamber for removal and replacement of the filter.