Substrate Etching Sequence for Narrow Gap Penetration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing substrate processing methods inefficiently etch targets disposed both inside and outside gaps due to continuous use of the same etching liquid, leading to excessive component usage and limited penetration into narrow spaces.
Innovation Solution
A method involving an outer etching step with a standard etching liquid followed by an inner etching step using a mixed etching liquid with lower surface tension to penetrate gaps, allowing separate etching of outer and inner portions, and a rinse step to remove residual liquids.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the same etching liquid is continuously supplied from start to end of etching processing, then the etching process is simple to operate, but the usage of etching components is excessive and the etching liquid cannot efficiently penetrate narrow gap structures
Solution Approach 1:
The etching process is divided into two distinct stages: first etching (for outer portions) and second etching (for inner portions). Different etching liquids are supplied in sequence - a standard etching liquid is used initially, then a mixed etching liquid containing low-surface-tension liquid is supplied to penetrate the gap structure. This segmentation allows each etching liquid to be optimized for its specific function, reducing overall component usage while maintaining process effectiveness.
Solution Approach 2:
The surface tension parameter of the etching liquid is changed between the two etching stages. The first etching uses a standard etching liquid with normal surface tension, while the second etching uses a mixed etching liquid with reduced surface tension (achieved by adding low-surface-tension liquid). This parameter change enables the second etching liquid to efficiently penetrate the narrow gap structure, solving the penetration problem without requiring continuous use of high-component etching liquid throughout the entire process.
2Quantity of substance
If a standard etching liquid is used for both outer and inner etching, then the process is easier to control, but the etching liquid cannot effectively enter the narrow gap space
Solution Approach 1:
The surface tension parameter of the etching liquid is modified by adding low-surface-tension liquid to create a mixed etching liquid. This parameter change enables the etching liquid to effectively penetrate the narrow gap structure by reducing surface tension forces that would otherwise prevent entry into the tight space. The change is implemented only in the second etching stage, maintaining process control simplicity while achieving effective penetration.
Solution Approach 2:
The outer portions of the etching target are etched first using the standard etching liquid before supplying the mixed etching liquid for inner etching. This preliminary action removes material from the outer regions, potentially opening up the gap structure and making it more accessible to the subsequent mixed etching liquid, thereby facilitating better penetration into the narrow gap space.
3Loss of substance
If the same etching liquid is used throughout the process, then fewer liquid types need to be managed, but component usage is excessive and waste increases
Solution Approach 1:
The etching process is segmented into two stages with different liquid compositions. The first etching uses a standard etching liquid optimized for outer portion etching, while the second etching uses a mixed etching liquid with low-surface-tension liquid added for efficient gap penetration. This segmentation ensures that the high-component mixed etching liquid is used only when necessary (in the second stage), thereby reducing overall component waste while managing a limited number of liquid types.
Solution Approach 2:
The composition parameter of the etching liquid is changed only in the second etching stage by adding low-surface-tension liquid. This targeted parameter change allows the process to achieve effective gap penetration only when needed, rather than using the high-component mixed liquid throughout the entire process. This approach reduces overall component consumption and waste while keeping the number of liquid types manageable.
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 reduces the usage of etching components and effectively etches both outer and inner portions of the etching target, ensuring thorough processing while minimizing waste.
Implementation Method 1
a low-surface-tension liquid having a surface tension smaller than a surface tension of the etching liquid is dissolved
Data Source
Figure 1~2B
Figure 3A~3C
Figure 3D~3F
AI summary
A substrate processing method includes an outer etching step of etching an outer portion by supplying an etching liquid to a substrate including an end surface, an inner surface forming a gap which has a width smaller than a depth of the gap and is open at the end surface, and the etching target having an outer portion disposed outside the gap and an inner portion disposed in the gap, and an inner etching step of etching the inner portion with a mixed etching liquid which has entered the gap by supplying, to the substrate, the mixed etching liquid which is an etching liquid obtained by dissolving a low-surface-tension liquid having a surface tension smaller than a surface tension of the etching liquid, after the outer portion of the etching target is etched.