Substrate Drying via Rear Surface Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In substrate processing, the use of low surface tension liquids for drying after chemical processing can lead to pattern collapse due to surface tension effects, especially when the spin dry step is prolonged, causing heat loss and increased surface tension impulse on the pattern.
Innovation Solution
A substrate processing method involving a low surface tension liquid replacement step followed by a post-heating step, where a heating fluid is supplied to the rear surface after stopping the low surface tension liquid supply, allowing for a quicker spin dry step at a higher substrate temperature, thereby reducing pattern collapse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a low surface tension liquid (organic solvent) is supplied to replace rinse liquid before spin dry, then pattern collapse is alleviated, but the spin dry step takes longer and surface tension impulse increases
Solution Approach 1:
The patent changes the temperature parameter of the substrate by supplying heating liquid to the rear surface, raising the substrate temperature before spin dry. This parameter change reduces the viscosity and surface tension of the organic solvent, enabling faster spin dry while maintaining pattern integrity.
Solution Approach 2:
The patent performs preliminary heating of the substrate before the spin dry step by supplying heating liquid to the rear surface. This preliminary action prepares the substrate in advance, ensuring that the spin dry can be completed quickly without causing pattern collapse.
2Reliability
If the spin dry step is prolonged to dry the substrate thoroughly, then drying completeness is improved, but heat loss increases and pattern collapse risk increases
Solution Approach 1:
By changing the temperature parameter through preliminary heating, the organic solvent's viscosity and surface tension are reduced, allowing rapid evaporation and drying. This achieves complete drying in a shorter time, reducing heat loss while maintaining drying effectiveness.
Solution Approach 2:
The patent rushes through the spin dry step by performing preliminary heating, enabling the drying process to be completed quickly without prolonged exposure to surface tension forces, thus minimizing both heat loss and pattern collapse risk.
3Adaptability or versatility
If heating liquid is supplied to the rear surface during low surface tension liquid supply, then replaceability is enhanced, but substrate temperature decreases due to heat removal by the liquid
Solution Approach 1:
The patent performs preliminary heating to the extent needed before spin dry, then stops the heating liquid supply. This preliminary action achieves sufficient temperature rise without continuous heat removal during spin dry, maintaining both replaceability and temperature.
Solution Approach 2:
The patent applies partial heating - enough to raise substrate temperature and reduce solvent viscosity for fast spin dry, but not excessive heating that would cause other problems. The heating liquid supply is stopped at the appropriate moment to avoid unnecessary heat removal.
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 effectively shortens the spin dry time, minimizing the surface tension impulse on the pattern and reducing heat loss, thus enhancing the preservation of the substrate pattern.
Implementation Method 1
a post-heating step of supplying the heating fluid to the rear surface on the side opposite to the front surface of the substrate, in a state in which the supply of the low surface tension liquid to the front surface is stopped, before start of the spin dry step
Implementation Method 2
a spin dry step of rotating, after completion of the replacement step, the substrate about a predetermined rotation axis to spin off the low surface tension liquid
Data Source
AI summary
A substrate processing method includes a replacement step of replacing a rinse liquid adhered to the front surface of a substrate with a low surface tension liquid whose surface tension is lower than that of the rinse liquid, where the replacement step includes a low surface tension liquid supply step of supplying the low surface tension liquid to the front surface while supplying a heating fluid to the rear surface on a side opposite to the front surface and a post-heating step of supplying the heating fluid to the rear surface on the side opposite to the front surface of the substrate, in a state in which the supply of the low surface tension liquid to the front surface is stopped, before the start of a spin dry step after the completion of the low surface tension liquid supply step.