Wafer Cleaning with Protonated Solution to Suppress Static Charge
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in semiconductor manufacturing is the accumulation of static electricity on wafer surfaces during the cleaning process, leading to device failure and reduced yield due to electric discharge.
Innovation Solution
A wafer cleaning method using a protonated cleaning solution with a protonator comprising an anodic and cathodic electrodes, followed by purging with a drying gas to minimize surface charge and prevent static electricity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wet cleaning is used to remove impurities from wafer surface, then cleaning effectiveness is improved, but static electricity accumulates on the wafer surface causing device failure
Solution Approach 1:
A protonated cleaning solution is introduced as an intermediary substance between the wafer surface and the drying process. The protonated solution (with excess H+ ions) serves as a mediator that suppresses negative charge accumulation on the wafer surface during cleaning, thereby preventing static electricity buildup while maintaining effective impurity removal
Solution Approach 2:
The chemical parameter of the cleaning solution is changed by protonating it (adding excess hydrogen ions). This parameter change transforms the cleaning solution from a neutral state to a protonated state, which fundamentally alters its interaction with the wafer surface and prevents negative charging during the cleaning process
2Loss of time
If nitrogen purging and high-speed spinning are used for drying, then drying time is reduced, but negative charging of the wafer surface occurs
Solution Approach 1:
The wafer surface is pre-treated with a protonated cleaning solution before the drying process. This preliminary action ensures that the wafer surface has excess hydrogen ions already present, which counteract the negative charging effect that would normally occur during high-speed spinning and nitrogen purging
Solution Approach 2:
The protonated cleaning solution acts as a cushioning layer that protects the wafer surface from negative charging during drying. The excess H+ ions in the protonated solution create a protective effect that prevents the accumulation of negative charges even under the mechanical stress of high-speed spinning
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 method effectively reduces device failure by suppressing static electricity, thereby increasing the overall yield of integrated circuit manufacturing.
Implementation Method 1
protonating a cleaning solution with a protonator comprising an anodic electrode and a cathodic electrode covered on its surface with an inert film
Implementation Method 2
cleaning a wafer surface with the protonated cleaning solution so that the cleaned wafer surface carries an amount of negative charge smaller than an amount of negative charge present on a wafer surface that has been cleaned with a non-protonated cleaning solution
Data Source
AI summary
The present invention provides a wafer cleaning method and a method for manufacturing semiconductor device. The wafer cleaning method includes: protonating a cleaning solution with a protonator; cleaning a wafer surface with the protonated cleaning solution so that the cleaned wafer surface carries an amount of negative charge smaller than an amount of negative charge present on a wafer surface that has been cleaned with a non-protonated cleaning solution and is covered with a liquid film of the cleaning solution; and purging the wafer surface with a drying gas to remove the liquid film from a center of the wafer surface towards its periphery. The technique proposed in the present invention is able to desirably suppress static electricity on a wafer surface and effectively reduce device failure that may be caused by static electricity, thereby increasing overall yield of integrated circuit manufacture.