Intermediate Tank Pressure Control for Bubble-Free Liquid Supply
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor manufacturing, the use of pressurized gas to transport processing liquids can lead to gas dissolution and bubble generation, resulting in non-uniform coating and defects in the film during photolithography processes.
Innovation Solution
A processing liquid supplying apparatus that evacuates an intermediate tank connected to the processing liquid source, using a pressure-adjusting unit to return the pressure from reduced to normal, preventing gas dissolution and allowing for bubble-free transportation of the processing liquid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If pressurized gas is used to transport processing liquid, then the processing liquid can be transported from the container to the nozzle, but gas dissolves in the processing liquid and bubbles are generated
Solution Approach 1:
The patent divides the processing liquid supply system into multiple independent intermediate tanks instead of using a single continuous pressurized line. Each tank operates independently with its own evacuation and pressure adjustment cycles, preventing gas dissolution that would occur in continuous pressurized flow while still enabling efficient liquid transportation to the nozzle.
Solution Approach 2:
The system performs preliminary evacuation of intermediate tanks before filling them with processing liquid. By creating a vacuum state first, the tanks are prepared to receive liquid without introducing gas that would dissolve into the liquid. This preliminary action prevents bubble formation before the transportation process begins.
2Quantity of substance
If the interior of the container is pressurized to push out the processing liquid, then the processing liquid can be transported toward the nozzle, but the pressure fluctuation causes gas to be released and generate bubbles
Solution Approach 1:
The patent implements dynamic pressure control by sequentially evacuating and pressurizing multiple intermediate tanks in a cyclic manner. Instead of maintaining constant high pressure that causes gas release, the system dynamically adjusts pressure levels - creating vacuum to draw liquid, then briefly pressurizing to push liquid forward - thereby controlling flow rate while minimizing bubble generation.
Solution Approach 2:
The system uses periodic evacuation and pressure adjustment cycles for each intermediate tank. Each tank undergoes repeated cycles of being evacuated, filled with processing liquid, pressurized to push liquid toward the nozzle, and then evacuated again. This periodic action maintains steady overall flow while preventing continuous pressure-induced bubble formation.
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 prevents bubble generation in the processing liquid, ensuring uniform coating and reducing defects during semiconductor manufacturing processes, even when the processing liquid source is not directly accessible, such as during container replacement.
Implementation Method 1
an evacuating unit that evacuates an interior of the intermediate tank to transport the processing liquid from the processing liquid source to the intermediate tank through the transport line
Implementation Method 2
a pressure adjusting unit that supplies a gas into the intermediate tank to return a pressure in the evacuated intermediate tank from a reduced pressure to a normal pressure
Data Source
AI summary
A processing liquid supplying apparatus supplies a processing liquid to a process object via a discharging part. In one embodiment, the apparatus includes: a processing liquid source that supplies a processing liquid; an intermediate tank connected to the processing liquid source via a transport line; a feed line provided between the intermediate tank and the discharging part; an evacuating unit that evacuates an interior of the intermediate tank to transport the processing liquid from the processing liquid source to the intermediate tank through the transport line; and a pressure adjusting unit that supplies a gas into the intermediate tank to return a pressure in the evacuated intermediate tank from a reduced pressure to a normal pressure, thereby to place the intermediate tank ready for feeding the processing liquid, having been transported into the intermediate tank, into the feed line.