Substrate Freeze-Cleaning with Supercooled Film Cracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing freeze-cleaning method for substrates, such as semiconductor wafers and photolithography masks, has a limited removal ratio of contaminants, necessitating an improvement in contamination removal efficiency.
Innovation Solution
A substrate treatment device that includes a placement stand for rotating the substrate, a cooling part for supplying a cooling gas, a liquid supplier for forming a supercooled liquid film, and a controller to manage the rotation speed, cooling gas flow rate, and liquid supply, which induces cracking in the frozen film to separate contaminants, thereby enhancing the removal ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional freeze-cleaning method is used, then contaminations can be removed from the substrate surface, but the removal ratio is insufficient
Solution Approach 1:
The patent applies parameter changes by controlling the substrate temperature to be below the freezing point of water (e.g., -10°C to -50°C) and adjusting the liquid supply amount and cooling gas flow rate to create optimal conditions for freeze-cleaning. This temperature parameter control enables the water film to freeze and form ice that traps contaminants, thereby improving the removal ratio while maintaining cleaning efficiency
Solution Approach 2:
The patent utilizes phase transitions by supplying liquid water to the substrate surface, which then freezes into ice film when the substrate temperature is below the freezing point. The phase change from liquid to solid traps contaminants within the ice structure, and subsequent melting and rinsing removes the trapped contaminants, achieving high removal ratio and improved cleaning efficiency
2Manufacturing precision
If the liquid supply amount is increased to improve contamination removal, then more contaminants can be removed, but the cleaning process becomes less efficient
Solution Approach 1:
The patent applies partial action by supplying liquid water in controlled amounts that are sufficient to form a complete water film on the substrate surface but not excessive. The liquid supply amount is optimized to create just enough water film that will freeze and trap contaminants, avoiding waste of liquid and reducing the time required for subsequent melting and rinsing steps, thus improving overall cleaning efficiency
Solution Approach 2:
The patent replaces mechanical cleaning methods with a thermal-based freeze-cleaning mechanism. Instead of using mechanical scrubbing or high-pressure washing that would require significant time and force, the system uses temperature control to freeze and melt water films, leveraging phase transitions to remove contaminants more efficiently with reduced process time
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 device achieves a higher removal ratio of contaminants by maintaining the substrate in a supercooled state and inducing cracking in the frozen film, improving the efficiency and productivity of the freeze-cleaning process.
Implementation Method 1
a cooling part configured to supply a cooling gas into a space between the placement stand and the substrate
Implementation Method 2
forms a frozen film by freezing the liquid in the super cooled state
Implementation Method 3
causes crack to generate in the frozen film by decreasing a temperature of the frozen film
Data Source
AI summary
According to one embodiment, a substrate treatment device includes a placement stand configured to rotate a substrate, a cooling part configured to supply a cooling gas into a space between the placement stand and the substrate, a liquid supplier configured to supply a liquid on a surface of the substrate opposite to the placement stand, and a controller controlling a rotation speed of the substrate, a flow rate of the cooling gas, or a supply amount of the liquid. The controller sets the liquid on the surface of the substrate to be in a supercooled state, forms a frozen film by freezing the liquid in the super cooled state, and causes crack to generate in the frozen film by decreasing a temperature of the frozen film.