Wafer IPA Vapor Drying With Distilled Rinse for Low Particle Cleaning
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Solution Overview
Problem
Existing wafer cleaning processes using liquid isopropyl alcohol (IPA) introduce significant particle contamination and struggle with non-uniform drying due to mechanical pumps and valves, and nitride gas displacement is inefficient.
Innovation Solution
A wafer cleaning method and system utilizing vaporized IPA and distilled high purity liquid IPA, where IPA is evaporated, filtered, and condensed back into liquid form for rinsing and drying, reducing contamination and ensuring a uniform removal front.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If liquid IPA is used for rinsing and drying wafers, then the wafer cleaning process can be performed, but significant particle contamination is introduced
Solution Approach 1:
The patent changes the physical state of IPA from liquid to vapor form for the drying process. By using IPA vapor instead of liquid IPA, the system eliminates particle contamination while maintaining effective wafer cleaning. The vapor phase allows for uniform distribution and removal of contaminants without introducing particles from liquid handling equipment.
Solution Approach 2:
The patent replaces mechanical liquid handling systems (pumps, valves, spray nozzles) with a vapor delivery system. This substitution eliminates the mechanical components that generate particle contamination in liquid IPA systems, achieving contamination-free wafer processing while maintaining cleaning effectiveness.
2Productivity
If liquid IPA is used with mechanical pumps and valves, then the wafer cleaning process can be performed, but non-uniform drying occurs
Solution Approach 1:
The patent changes the phase of IPA from liquid to vapor, which fundamentally alters the delivery and distribution characteristics. Vapor phase IPA provides uniform distribution across the wafer surface through diffusion and convection, eliminating the non-uniform drying patterns caused by liquid spray systems and mechanical handling.
3Productivity
If nitride gas is used to displace liquid IPA, then drying can be achieved, but the displacement is inefficient
Solution Approach 1:
The patent changes IPA to vapor phase, which allows for direct evaporation and displacement without requiring gas-phase displacement. The vapor naturally disperses and evaporates more efficiently than liquid IPA can be displaced by nitride gas, reducing drying time and improving overall process efficiency.
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
Reduces particle contamination and achieves a uniform drying process by using vaporized IPA and distilled liquid IPA, enhancing the cleaning efficiency and reducing contamination risks.
Implementation Method 1
liquid isopropyl alcohol (IPA) is evaporated into IPA vapor by an IPA evaporation system
Implementation Method 2
a portion of the IPA vapor is condensed into distilled high purity liquid IPA by an IPA condensation system
Data Source
AI summary
A wafer processing method and system are provided. The wafer processing system includes an isopropyl alcohol (IPA) evaporation system, an IPA condensation system, and a process chamber. The IPA evaporation system evaporates liquid IPA into IPA vapor. The IPA condensation system condenses a portion of the IPA vapor into distilled high purity liquid IPA. The process chamber rinses a semiconductor wafer in the process chamber using the distilled high purity liquid IPA, and displaces the distilled high purity liquid IPA using a remaining portion of the IPA vapor to dry the semiconductor wafer.