Dual-Slit Pneumatic Wafer Drying Apparatus
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Solution Overview
Problem
Current drying methods in lithography systems, such as spin drying, air knife drying, Marangoni drying, and wiper-based methods, face issues like residual droplets, contamination, and inefficient drying speeds, which can damage wafers and disrupt the lithography process. Additionally, existing systems are often bulky or introduce unwanted vibrations, making them unsuitable for industrial applications.
Innovation Solution
A compact drying apparatus with two slits, one for supplying pressurized gas and the other for suction, traverses along the wafer to remove droplets by directing the gas flow parallel to the wafer movement, ensuring controlled and complete drying without physical contact, thus preventing contamination and maintaining the wafer's temperature stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If spin drying is used to remove liquid droplets from the wafer, then drying speed is improved, but vibrations are introduced and footprint increases
Solution Approach 1:
The invention replaces mechanical spin drying with a pneumatic system. A gas flow is directed across the wafer surface through a gas supply device, creating a pressure difference that removes liquid droplets without mechanical rotation. This eliminates vibrations while maintaining effective drying, directly resolving the contradiction between drying speed and vibration introduction.
2Productivity
If off-axis spin drying is used to remove droplets, then drying effectiveness is improved, but footprint of the apparatus increases
Solution Approach 1:
The pneumatic drying system uses a gas flow directed across the wafer surface to remove droplets. The gas supply device can be positioned close to the wafer and directed along its length, achieving effective droplet removal without requiring the large off-axis rotation space. This reduces the apparatus footprint while maintaining drying effectiveness.
3Productivity
If air knife drying is used to blow away droplets, then drying speed is improved, but contamination of the system occurs
Solution Approach 1:
The invention extracts and removes the liquid droplets from the system using a controlled gas flow. The gas supply device directs gas across the wafer surface, and the resulting pressure difference draws droplets into a removal zone where they are extracted from the system. This prevents contaminated gas from being recirculated or blown back into the system, resolving the contamination issue while maintaining drying speed.
Solution Approach 2:
The system uses a controlled gas flow where the gas enters through a supply device, interacts with the wafer surface to remove droplets, and then exits through a controlled path. This feedback-controlled flow ensures that gas does not blow contaminants back into the system but rather carries them away in a controlled manner, preventing system contamination.
4Productivity
If wiper-based drying is used to remove droplets, then contact drying is achieved, but contamination of the wafer occurs
Solution Approach 1:
The invention replaces contact-based wiper drying with a pneumatic system. Gas flow across the wafer surface creates a pressure difference that removes droplets without physical contact. This eliminates the contamination risk associated with wipers touching the wafer surface while achieving complete drying, directly resolving the contradiction between drying completeness and contamination prevention.
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 effectively removes all droplets in a controlled manner, preventing contamination and ensuring the wafer is dry and contamination-free, while maintaining temperature stability, thus enhancing the lithography process's precision and efficiency.
Implementation Method 1
a gas flow is directed across a surface of the target... removing liquid droplets from the target
Data Source
AI summary
The invention relates to a drying apparatus for use in a lithography system for drying at least part of a surface on a first side of a planar target, such as a wafer. The apparatus has a drying device for eliminating liquid or droplets thereof from the first side of the planar target. The drying device has a first slit and a second slit arranged in close proximity of the target. A gap is present between the target and the drying device. Pressurized gas may be supplied via the first slit into the gap. The liquid may be discharged from the target by means of the pressurized gas through the second slit. The first and the second slit are configured to enable the pressurized gas to flow along the first side of the planar target substantially parallel to the planar target.