Substrate Treatment Temperature Control for Uniformity
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Solution Overview
Problem
Existing substrate treatment apparatuses face challenges in achieving uniform temperature distribution across substrates due to temperature variations caused by centrifugal forces and evaporation, leading to reduced treatment uniformity.
Innovation Solution
A substrate treatment apparatus with a chamber, a substrate holding/rotating unit, a treatment liquid supplying unit, a temperature measuring unit, a temperature adjusting unit, and a controller that adjusts the internal air temperature and treatment liquid temperature to maintain a predetermined relationship, ensuring uniform temperature distribution by compensating heat loss and evaporation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If higher-temperature treatment liquid is supplied to the center portion of the rotating substrate, then the treatment liquid can be supplied over the entire upper surface of the substrate, but the temperature uniformity of the treatment liquid on the substrate is reduced
Solution Approach 1:
The patent applies local quality by supplying treatment liquid at different temperatures to different regions of the substrate. Specifically, higher-temperature treatment liquid is supplied to the center portion while lower-temperature treatment liquid is supplied to the peripheral portion, allowing each region to receive optimally temperature-controlled liquid that compensates for the cooling effects of rotation and evaporation at different locations.
Solution Approach 2:
The patent changes the temperature parameter of the treatment liquid based on the radial position on the substrate. By adjusting the temperature of the treatment liquid supplied to different regions (center vs. periphery), the system compensates for the temperature non-uniformity caused by centrifugal forces and evaporation, thereby maintaining overall temperature uniformity across the substrate surface.
2Speed
If the substrate rotates at high speed to move treatment liquid from center to periphery, then the treatment liquid can be distributed across the entire substrate surface, but the peripheral portion is more liable to be cooled due to higher speed and evaporation
Solution Approach 1:
The patent applies preliminary anti-action by preemptively compensating for the expected cooling effect at the peripheral portion. Before the treatment liquid reaches the periphery and undergoes cooling from evaporation and high-speed rotation, lower-temperature treatment liquid is supplied to that region, counterbalancing the anticipated temperature drop and maintaining uniform temperature distribution.
Solution Approach 2:
The patent recognizes that different regions of the rotating substrate experience different cooling conditions, with the periphery experiencing more severe cooling due to higher linear speed and greater evaporation. By applying local quality control, the system supplies temperature-adjusted treatment liquid specifically to the peripheral portion to compensate for these localized effects.
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 apparatus enhances the uniformity of the treatment liquid temperature across the substrate, improving the overall treatment process by maintaining a consistent temperature difference between the center and peripheral portions.
Implementation Method 1
The higher-temperature treatment liquid spouted from the nozzle reaches the center portion of the upper surface of the substrate and then spreads outward on the substrate by a centrifugal force
Implementation Method 2
Further, the treatment liquid is partly evaporated while removing heat from the ambient environment during the outward movement of the treatment liquid on the substrate. Accordingly, the temperature of the treatment liquid is further reduced.
Data Source
AI summary
A substrate treatment apparatus includes: a chamber; a substrate being treated with a treatment liquid in the chamber; a temperature measuring unit which measures an internal air temperature of the chamber and/or a temperature of the treatment liquid; a temperature adjusting unit which changes the internal air temperature and/or the temperature of the treatment liquid; a storage unit which stores a map defining a relationship between the air temperature and the treatment liquid temperature so that a treatment liquid temperature level for a given air temperature level is lower than the given air temperature level; and a temperature controlling unit which sets a target value of the internal air temperature of the chamber or the temperature of the treatment liquid based on the map and a measurement value detected by the temperature measuring unit, and controls the temperature adjusting unit based on the target value.