Substrate Drying Using Sublimation Agent Film
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing substrate drying methods face challenges in forming a solid sublimation-agent film without contamination from water, which can lead to pattern collapse and reduced efficiency in the sublimation drying process, particularly due to the need for ultra-low-temperature nitrogen gas and high equipment costs.
Innovation Solution
A method involving the use of a liquid sublimation agent with a low freezing point and a high vapor-pressure liquid that does not include water, where the high vapor-pressure liquid is supplied to the substrate's rear surface to cool and solidify the sublimation agent film, preventing water contamination and allowing for efficient sublimation drying without the need for costly temperature control units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ultra-low-temperature nitrogen gas is supplied to form a frozen film for sublimation drying, then pattern collapse is prevented, but equipment cost and running costs become enormous
Solution Approach 1:
The patent replaces expensive, complex ultra-low-temperature nitrogen gas supply equipment with a simple, inexpensive liquid sublimation agent that can be easily applied and disposed of. The liquid sublimation agent forms a temporary frozen film on the substrate surface, performs its sublimation drying function, and then evaporates completely, eliminating the need for costly temperature control equipment and continuous gas supply systems.
Solution Approach 2:
The patent changes the physical state and temperature parameters from ultra-low-temperature gas (−60°C nitrogen gas) to near-ambient temperature liquid sublimation agent. This parameter change dramatically simplifies the equipment requirements while maintaining the sublimation drying effect, as the liquid sublimation agent freezes on contact with the substrate and subsequent heating, forming the necessary frozen film without requiring ultra-low-temperature infrastructure.
2Manufacturing precision
If cold water is supplied to the rear surface to solidify the sublimation agent, then a sublimation-agent film is formed, but water may mix with the sublimation-agent film and obstruct sublimation or cause pattern collapse
Solution Approach 1:
The patent introduces a temperature-controlling fluid as an intermediary substance that mediates between the heating system and the liquid sublimation agent. This fluid transfers thermal energy to the substrate rear surface, causing the liquid sublimation agent on the front surface to freeze and form a uniform frozen film, while the fluid itself does not come into direct contact with the sublimation agent film, thus preventing contamination.
Solution Approach 2:
The patent applies temperature control from the rear surface dimension rather than directly from the front surface where the sublimation agent is applied. This spatial separation allows thermal energy to be transferred through the substrate thickness to the liquid sublimation agent, freezing it into a uniform film without introducing water or other contaminants from the heating system into the sublimation agent film.
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 effectively forms a solid sublimation-agent film while preventing water contamination, enabling efficient sublimation drying and reducing operational costs by eliminating the requirement for expensive temperature control units and ultra-low-temperature nitrogen gas.
Implementation Method 1
a high vapor-pressure liquid that has vapor pressure higher than the sublimation agent... losing vaporization heat in response to vaporization of the high vapor-pressure liquid
Implementation Method 2
cooling the sublimation agent, and, as a result, solidifying the liquid film of the sublimation agent
Implementation Method 3
a sublimating step of sublimating the sublimation-agent film
Data Source
AI summary
A substrate drying method for drying a front surface of a substrate having a pattern includes a sublimation-agent-liquid-film placing step of placing a liquid film of a liquid sublimation-agent on the front surface of the substrate, a high vapor-pressure liquid placing step of placing a liquid film of a high vapor-pressure liquid that has vapor pressure higher than the sublimation agent and that does not include water on the liquid film of the sublimation-agent placed on the front surface of the substrate, a vaporizing/cooling step of losing vaporization heat in response to vaporization of the high vapor-pressure liquid, and, cooling the sublimation-agent, and, as a result, solidifying the liquid film of the sublimation-agent, and, forming a sublimation-agent film on the front surface of the substrate, and a sublimating step of sublimating the sublimation-agent film.