Substrate Drying with Controlled Dry-Region Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional substrate processing methods face challenges in effectively drying substrates with resist patterns due to differences in hydrophilicity, leading to residual droplets and defects from minute droplet residues during the spin drying process.
Innovation Solution
A combination drying method is employed, where a cleaning liquid is supplied to the substrate while a dry gas is injected to form and expand a dry region, controlling the interface between the liquid and dry regions to prevent droplet residue formation, using a substrate processing apparatus with a cleaning liquid nozzle and a gas nozzle controlled by a monitoring mechanism to adjust the drying process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If spin drying is used to dry substrates, then drying efficiency is improved, but residual droplets and defects occur due to differences in hydrophilicity of resist patterns
Solution Approach 1:
The patent applies local quality by creating a dry region with specific properties (low humidity) at a particular location on the substrate, rather than uniformly drying the entire substrate. The dry region is formed by controlling the interface between cleaning liquid and gas, allowing different regions of the substrate to have different drying characteristics appropriate to their specific needs.
Solution Approach 2:
The patent changes the physical parameters of the drying environment by controlling the interface movement speed between liquid and gas phases. By adjusting the speed at which the dry region expands across the substrate, the system optimizes drying conditions to prevent droplet residue while maintaining high drying efficiency.
2Reliability
If cleaning liquid is supplied to form a liquid layer, then cleaning effectiveness is improved, but droplet residues remain on the substrate surface
Solution Approach 1:
The patent applies preliminary action by forming a dry region before the cleaning liquid completely dries naturally. The dry region is created and expanded across the substrate surface in advance, preventing droplet residue formation by controlling the evaporation and drying process before harmful residues can form.
Solution Approach 2:
The patent uses a gas phase as an intermediary substance to transition the substrate from wet to dry state. The gas acts as a mediator between the cleaning liquid and the final dry substrate surface, allowing controlled removal of cleaning liquid without direct contact that would cause droplet residue.
3Device complexity
If conventional drying methods are used, then process simplicity is maintained, but watermark defects occur due to uncontrolled drying
Solution Approach 1:
The patent applies dynamics by making the drying process adaptive and controllable rather than static. The interface between cleaning liquid and gas is dynamically controlled to move across the substrate at a regulated speed, allowing the drying process to adapt to different substrate conditions and prevent watermark defects while maintaining reasonable process complexity.
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 method suppresses the generation of defects from residual droplets by maintaining a controlled dry region expansion, ensuring thorough drying and reducing the risk of watermark formation on substrates.
Implementation Method 1
supplying a gas onto the substrate under processing to partially remove a cleaning liquid layer formed on the substrate and thereby form a dry region on a central portion of the substrate
Data Source
AI summary
A substrate processing apparatus for cleaning and drying a substrate under processing, including supplying a cleaning liquid onto the substrate under processing to form a cleaning liquid layer, supplying a gas onto the substrate under processing to partially remove the cleaning liquid layer and thus generate a first dry region on the substrate under processing, expanding the first dry region to generate a second dry region by controlling the movement speed of the boundary between the cleaning liquid layer and the first dry region to be less than or equal to a predetermined speed, and further expanding the second dry region to generate a third dry region.