Shower Head Segmentation for Rapid Purging in Film Forming
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Solution Overview
Problem
In film forming apparatuses like PE-ALD and ALD, the existing shower heads face issues with gas passage purging, leading to degradation in film forming quality due to residual gases, requiring increased purge times to avoid this problem.
Innovation Solution
The design of a shower head with independent first and second passages, where the upper walls of both passages are slanted to reduce height with distance from the thin holes, allowing for efficient radial gas spread and rapid purging through multiple thin holes, facilitating quick removal of gases from the passages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If purge time is increased to remove residual gas from passages, then film forming quality is maintained, but processing efficiency decreases
Solution Approach 1:
The shower head is divided into multiple independent flow passages (first passage, second passage, etc.), each capable of being purged independently. This segmentation allows different passages to be purged at different times, enabling overlapping purge and film formation operations across different passages, thus reducing total purge time while maintaining film quality.
Solution Approach 2:
The system employs periodic alternation between different gas supply modes: first gas supplied via first passage, then purge gas via first passage; second gas supplied via second passage, then purge gas via second passage. This periodic action pattern allows efficient cycling through multiple gases and purges without requiring all passages to be purged sequentially to maximum duration.
2Productivity
If purge time is reduced to improve processing efficiency, then productivity increases, but residual gas remains causing degradation in film forming quality
Solution Approach 1:
By segmenting the gas supply system into multiple independent passages, the invention allows parallel processing where one passage is being purged while another is being used for film formation. This eliminates the need to wait for complete purge of all passages before proceeding with film formation, thus improving productivity without sacrificing film quality.
Solution Approach 2:
The system performs preliminary purging actions in advance by dedicating specific passages to purge functions while other passages are used for film formation. This preliminary action of purging one passage while simultaneously forming film on another allows the system to maintain readiness for the next film formation cycle without extending total processing time.
3Productivity
If multiple independent passages are used to enable parallel gas supply, then film formation efficiency improves, but passage purging becomes more complex
Solution Approach 1:
Each flow passage is designed to be multi-functional: it can supply different types of gases (first gas, second gas, purge gas) at different times. This universality means that the same physical passage structure handles multiple functions through temporal separation, reducing the need for additional dedicated purge passages and simplifying the overall system architecture despite having multiple passages.
Solution Approach 2:
The system uses periodic switching between different gas supply configurations: first gas through first passage, then purge gas through first passage; second gas through second passage, then purge gas through second passage. This periodic action creates a predictable, repeating pattern that simplifies control logic and reduces purging complexity by establishing a clear cycle rather than requiring complex real-time decision-making.
Data Source
AI summary
A film forming apparatus includes a susceptor, and a shower head provided above the susceptor and having a first passage and a second passage independent of the first passage formed therein, wherein the first passage is formed through the shower head by being provided with a first cavity surrounded by a first upper wall and a first lower wall, a first thin hole formed in the first upper wall, and a plurality of second thin holes formed in the first lower wall, the height of the first upper wall in the vertical direction is reduced with increase in distance from the first thin hole, and the second passage is formed in the same manner as the first passage.