Substrate Liquid Supply Pressure Regulation for Bubble-Free Coating
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Solution Overview
Problem
The generation of large amounts of bubbles in photoresist due to high gas pressure during application leads to insufficient film thickness and process defects in substrate processing.
Innovation Solution
A substrate processing apparatus with a gas supply unit that includes a regulator, resistors, and branch pipes to maintain a controlled gauge pressure in the liquid storage space, reducing gas dissolution and bubble formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high pressure gas is supplied to the bottle to transfer photoresist to the trap tank, then the photoresist transfer efficiency is improved, but the dissolved gas amount increases and bubbles are generated in the photoresist
Solution Approach 1:
The patent changes the pressure parameter by introducing a pressure regulation mechanism that maintains a controlled pressure difference between the bottle and trap tank. This allows the system to operate at lower pressure levels compared to direct high-pressure gas supply, reducing gas dissolution in the photoresist while still achieving effective transfer.
Solution Approach 2:
The patent introduces an intermediary pressure control system between the gas supply and the photoresist transfer process. This intermediary mechanism regulates the pressure to prevent excessive gas dissolution while maintaining sufficient transfer drive, acting as a buffer between the harmful high-pressure effect and the required transfer function.
2Speed
If high gas pressure is used to supply photoresist, then the liquid supply speed is improved, but the film thickness consistency deteriorates due to bubble formation
Solution Approach 1:
The patent modifies the pressure parameters to achieve an optimal balance point where sufficient flow speed is maintained but gas dissolution is minimized. The pressure regulation mechanism ensures that the system operates at the lowest necessary pressure to achieve required flow rates, thereby maintaining film thickness consistency.
Solution Approach 2:
The patent replaces the direct mechanical high-pressure gas supply system with a more sophisticated pressure-controlled system that uses regulated pressure differentials. This substitution allows for smoother, more controlled liquid flow that maintains consistent film thickness while achieving the required supply speed.
3Power
If the gas supply pressure is increased to maintain liquid flow, then the liquid delivery capability is improved, but the bubble-related process defects increase
Solution Approach 1:
The patent introduces an intermediary pressure control system that mediates between the gas supply and the liquid delivery process. This intermediary mechanism ensures that sufficient pressure is maintained for reliable liquid delivery while preventing the excessive pressure that causes bubble formation and process defects.
Solution Approach 2:
The patent implements a feedback mechanism through pressure regulation that continuously monitors and adjusts the pressure levels. This feedback control ensures that the system maintains optimal pressure for reliable liquid delivery while automatically preventing pressure excursions that would cause bubble-related defects.
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
Prevents excessive bubble generation, ensuring consistent liquid film thickness and improving substrate processing efficiency.
Implementation Method 1
a regulator installed upstream from a branch point where the branch pipe is branched from the main pipe in the main pipe to reduce pressure of the gas supplied from the gas supply source
Implementation Method 2
the high gas pressure increases the dissolved amount of gas in the photoresist stored in the bottle 9100
Implementation Method 3
a large amount of bubbles are generated in the photoresist as the photoresist flows along the supply pipes 9910 and 9930 or is applied onto the substrate W
Data Source
AI summary
Disclosed is a substrate processing apparatus including a liquid supply unit. The liquid supply unit includes: a bottle; a supply pipe for providing a path for a liquid in the bottle to flow to a liquid treating chamber; a trap tank installed in the supply pipe; a pump installed downstream of the trap tank in the supply pipe; and a gas supply unit for supplying gas. The gas supply unit includes: a main pipe; a branch pipe branched from the main pipe and connected to a storage space of the bottle; and a regulator installed upstream from a branch point where the branch pipe is branched from the main pipe in the main pipe to reduce pressure of gas supplied from the gas supply source.