Wafer Cleaning Stage Grip Pin Release to Prevent Chemical Stagnation
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Solution Overview
Problem
The existing semiconductor wafer cleaning processes face issues with wafer deterioration and stage damage due to liquid chemical contact during the photolithography development process, particularly at the point where the grip pin fixes the wafer.
Innovation Solution
A wafer cleaning apparatus and method that utilizes a chamber with a stage equipped with a grip pin and a nozzle to supply liquid chemicals, where the grip pin is designed with a connection groove and a hydrophobic material, allowing for the wafer to be fixed and rotated at different speeds for effective cleaning while preventing liquid chemical stagnation and inflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the grip pin is used to fix the wafer on the stage, then the wafer can be securely held and rotated during cleaning processes, but liquid chemical may stagnate around the grip pin and cause wafer deterioration or stage damage
Solution Approach 1:
The harmful effect of liquid chemical stagnation around the grip pin is eliminated by extracting the grip pin from the liquid chemical supply area. The grip pin is positioned only at the edge of the stage where it contacts the wafer, while the liquid chemical is supplied to the center area through a nozzle, creating spatial separation between the fixation function and the chemical treatment function.
Solution Approach 2:
The stage surface acts as an intermediary element that separates the grip pin from direct contact with liquid chemical. The grip pin contacts the wafer at the stage edge, while the liquid chemical flows across the stage surface from the center nozzle, using the stage as a barrier to prevent chemical accumulation around the grip pin.
2Productivity
If the wafer is rotated at high speed during cleaning, then cleaning efficiency is improved, but the grip pin may not be released in time causing contact damage
Solution Approach 1:
The grip pin is preliminarily positioned to contact the wafer edge for secure fixation before high-speed rotation begins. The sequence is carefully controlled: the grip pin engages the wafer first, then rotation starts, and the grip pin is released after the wafer is securely held and the cleaning process is complete, preventing any contact damage during operation.
Solution Approach 2:
The grip pin system is made dynamic by allowing it to move between contact and non-contact states. The grip pin can be extended to contact the wafer edge when needed for fixation, and retracted or released when the wafer needs to rotate freely during cleaning, enabling the system to adapt its degree of constraint based on process requirements.
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 wafer deterioration and stage damage by ensuring the grip pin is moved away from the wafer during the development process, effectively guiding liquid chemicals outside the stage, thus maintaining wafer integrity and preventing chemical stagnation.
Implementation Method 1
The grip pin, at least a part of which is disposed inside of the connection groove and which is moved toward a center of the stage to fix the wafer
Implementation Method 2
a nozzle configured to supply liquid chemical to a wafer provided on the stage
Implementation Method 3
First ultrapure water is provided onto the wafer while it is rotating at a first rotation speed... while the wafer is rotating at a second rotation speed that is less than the first rotation speed
Implementation Method 4
A first liquid chemical guide portion is connected to the grip pin and is inclined with respect to a top surface of the stage
Data Source
AI summary
A wafer cleaning method is provided. The wafer cleaning method includes providing a wafer on a stage that is inside of a chamber. The wafer is fixed to the stage by moving a grip pin connected to an edge of the stage. First ultrapure water is supplied onto the wafer while the wafer is rotating at a first rotation speed. The grip pin is released from the wafer by moving the grip pin. A development process is performed by supplying liquid chemical onto the wafer while the wafer is rotating at a second rotation speed that is less than the first rotation speed.