Movable Substrate Engagement Members for Uniform Liquid Processing
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Solution Overview
Problem
Existing liquid processing apparatuses face challenges in ensuring that all areas of a substrate, such as semiconductor wafers, are effectively cleaned, as the peripheral edges are difficult to process due to the holding mechanism, leading to unprocessed areas.
Innovation Solution
A liquid processing apparatus with a substrate holding unit that includes movable engagement members and an elevating member, allowing for precise control of processing liquid application to both the top and bottom surfaces of the substrate, ensuring uniform processing by changing the engagement positions of the chuck members as the elevating member ascends and descends.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a substrate is held on a spin chuck for liquid processing, then the substrate can be rotated horizontally for cleaning, but the peripheral edges become difficult to process leading to unprocessed areas
Solution Approach 1:
The engagement members are made movable relative to the holding base, allowing them to dynamically adjust their position between an engaging position (contacting the substrate peripheral edge) and a non-engaging position (releasing the substrate). This dynamic adjustment enables the system to adapt during different processing phases, allowing processing liquid to reach areas previously inaccessible due to the static holding structure.
Solution Approach 2:
The engagement members are positioned to engage with the substrate peripheral edge before the liquid processing begins, holding the substrate securely. Then, during the processing cycle, the engagement members are retracted to a non-engaging position in advance of the liquid flow, ensuring that the processing liquid can uniformly cover the entire substrate surface including peripheral edges without obstruction.
2Reliability
If engagement members are used to hold the substrate, then the substrate can be securely held, but the engagement members block the processing liquid from reaching certain areas
Solution Approach 1:
The engagement members transition from a static holding structure to a dynamic system that can change position during operation. By moving between engaging and non-engaging positions, the system maintains substrate security when needed while eliminating obstructions to liquid processing when required, ensuring both reliability and processing completeness.
Solution Approach 2:
The engagement members operate periodically, alternating between engaging the substrate peripheral edge during loading/unloading phases and retracting during processing phases. This periodic action ensures the substrate is securely held during handling while allowing complete processing liquid coverage during the actual cleaning operation.
3Reliability
If the engagement members remain in the engaging position, then the substrate is securely held, but the processing cannot be performed on the peripheral areas
Solution Approach 1:
The engagement members are designed to be movable between engaging and non-engaging positions, allowing the system to switch between substrate holding mode and processing mode. During processing, the members retract to a non-engaging position, eliminating the shadow effect and ensuring uniform processing liquid distribution across the entire substrate surface including peripheral areas.
Data Source
AI summary
A liquid processing apparatus includes a substrate holding unit and an elevating member provided to ascend/descend with respect to the substrate holding unit. The substrate holding unit includes a holding base, and a first engagement member and a second engagement member which are provided to be movable in the holding base, and moved between an engaging position where the member is engaged with the peripheral edge of the substrate and a releasing position where the member releases the substrate. When the first contact unit connected to the first engagement member is in contact with a first portion to be contacted, the first engagement member is located at the engaging position. When the second contact unit connected to the second engagement member is in contact with a second portion to be contacted at a lower position than the first portion, the second engagement member is located at the engaging position.