Substrate Drying Apparatus Using Supercritical CO2 Temperature Control
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Solution Overview
Problem
Conventional drying processes for semiconductor substrates, especially those with fine circuit patterns, face challenges such as pattern collapse and inefficient removal of organic solvents due to temperature fluctuations and increased surface tension during the drying process, which can damage the substrate and reduce processing efficiency.
Innovation Solution
A substrate drying apparatus and method that utilize a temperature control unit to maintain different temperatures in the supply and branch lines of a fluid supply system, using supercritical carbon dioxide to dissolve and remove residual organic solvents, with a controller managing the fluid supply and exhaust steps to optimize temperature and pressure conditions, preventing substrate damage and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the process fluid is supplied to the chamber, then the substrate can be dried, but the temperature of the process fluid decreases due to adiabatic expansion causing increased surface tension and pattern damage
Solution Approach 1:
The process fluid is preheated to a temperature higher than the chamber temperature before being supplied to the chamber. This preliminary heating action compensates for the temperature drop that occurs during adiabatic expansion when the fluid enters the chamber, ensuring the fluid maintains sufficient temperature to prevent pattern collapse and substrate damage.
2Stability of the object's composition
If the temperature of the process fluid is increased to maintain stable conditions, then the surface tension increases affecting pattern, but the drying effectiveness decreases
Solution Approach 1:
The system dynamically adjusts the temperature parameter of the process fluid based on operational conditions. By controlling the fluid temperature within an optimal range (above chamber temperature but not excessively high), the system achieves both stable fluid properties and effective drying performance, balancing surface tension effects with drying efficiency.
3Device complexity
If conventional drying methods are used, then the process is simple, but pattern collapse occurs for fine circuit patterns with line width of 30 nm or less
Solution Approach 1:
The invention utilizes supercritical fluid phase transitions (supercritical CO2) as the drying medium. The process fluid transitions between liquid, vapor, and supercritical phases to achieve drying without causing pattern collapse. This phase transition approach maintains manufacturing precision for fine patterns while managing process complexity through controlled thermal and pressure conditions.
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 solution effectively prevents substrate damage and enhances processing efficiency by maintaining stable temperature and pressure conditions during the drying process, ensuring efficient removal of organic solvents and preventing pattern collapse, thus improving the overall drying efficiency for semiconductor substrates.
Implementation Method 1
the temperature of the process fluid is lowered due to an adiabatic expansion
Implementation Method 2
the temperature control unit may include a heater, and the heater may be installed only in the supply line of the supply line and the branch line
Implementation Method 3
using supercritical carbon dioxide to dissolve and remove residual organic solvents
Implementation Method 4
a substrate drying apparatus and method that utilize a temperature control unit to maintain different temperatures in the supply and branch lines of a fluid supply system, using supercritical carbon dioxide to dissolve and remove residual organic solvents
Data Source
AI summary
Disclosed is a substrate drying apparatus of substrate processing apparatus including a chamber that provides a space for processing a substrate, and a fluid supply unit that supplies a process fluid to the chamber, wherein the liquid supply unit includes a supply tank in which the fluid is stored, a supply line that connects the supply tank and the chamber, a branch line branched from a first point of the supply line and connected to a second point of the supply line, and a temperature control unit that adjusts the temperature of the fluid such that the temperatures of the fluids flowing through the supply line and the branch line between the first point and the second point are different.