Capillary Coating Nozzle Gap Control for Uniform Substrate Films
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Solution Overview
Problem
Existing substrate processing methods, such as capillary coating, face challenges in maintaining uniform film thickness due to variations in the positional relationship between the nozzle and substrate, leading to inefficiencies in processing liquid utilization and increased wastage.
Innovation Solution
A substrate processing apparatus and method involving a nozzle with a slit-like discharge port, where the substrate and nozzle are moved laterally with controlled gap adjustments and pressure changes to manage capillary action, ensuring uniform film thickness and minimizing liquid wastage by transitioning the liquid column from a contact to a non-contact state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If capillary coating method is used to form a film of processing liquid on substrate, then utilization efficiency of processing liquid is improved, but film thickness uniformity deteriorates due to variations in nozzle-substrate positional relationship
Solution Approach 1:
The patent applies dynamics by making the gap between the nozzle and substrate adjustable during the coating process. The gap is dynamically changed from a first gap (during coating) to a second gap (after coating), allowing the system to adapt to different process stages and maintain film thickness uniformity while preserving the liquid efficiency benefits of capillary coating.
Solution Approach 2:
The patent changes the physical parameter of the gap distance between nozzle and substrate. By controlling the gap to be within a specific range (0.1mm to 5mm) during coating and then increasing it after coating, the system optimizes both film thickness uniformity and processing liquid utilization efficiency.
2Productivity
If nozzle is separated from substrate after processing liquid application, then coating process is completed, but local thickening occurs due to liquid column breaking
Solution Approach 1:
The patent applies preliminary action by increasing the gap between nozzle and substrate before the liquid column actually breaks. This preliminary gap increase prevents the liquid column from breaking during nozzle separation, thereby avoiding local thickening and maintaining film thickness uniformity while completing the coating process.
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
The solution achieves uniform film thickness on the substrate while reducing wasteful consumption of processing liquid, preventing local thickening and excessive liquid draw, thus optimizing the coating process.
Implementation Method 1
The capillary coating method is a method of forming a gap between a nozzle and a substrate and drawing out a processing liquid from a slit-like discharge port onto the substrate by utilizing capillary action that occurs because the gap is filled with the processing liquid
Data Source
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AI summary
A substrate processing apparatus includes a nozzle block in which a slit-like discharge port is formed and a controller. The controller controls an X-direction driver and a Z-direction driver, so that a nozzle block is moved on a substrate with a gap between the nozzle block and the substrate filled with a processing liquid. At this time, the processing liquid is applied onto the substrate. Thereafter, the nozzle block is separated from the substrate, so that a liquid column connecting the nozzle block to the substrate is formed. The nozzle block is moved such that the liquid column changes from a liquid contact state in which the liquid column is in contact with the processing liquid present in a discharge port to a non-contact state in which the liquid column is not in contact with the processing present in the discharge port.