Efficient, inexpensive and environmentally friendly, this method allows removing, stripping and cleaning organic containing layers and residues from large substrates at room temperature.
There is a need for efficient and inexpensive method of removing, stripping or cleaning organic photoresists as well as other organic layer residues from large substrate surfaces. It is important that the method used to remove the photoresist not be reactive with the surface underlying the substrate.
The Methodology for Removing Microscopic Organic Contaminants
In this process the exposed surface is treated with a stripping solution comprising of ozone in a solvent of acetic anhydride. Optionally, the stripping solution along with acetic anhydride may have other co solvents like carbonates or ethylene glycol diacetate. The lower vapor pressure of acetic anhydride as compared to acetic acid helps to reduce the odor in the workplace attributable to the stripping solution. Also, the lower melting point of acetic anhydride compared to acetic acid ensures that unlike the later, acetic anhydride remains a liquid and hence can be used as a solvent up to -73˚C. As acetic anhydride has low vapor pressure, this process can be carried out in an atmospheric pressure exhaust system.
Competitive Advantage of the Organic Contaminant Removal Technology
This new technique for removing microscopic organic contaminants substantially decreases the number of processing steps required to clean organics, resulting in cost and time savings. The stripping solution is not detrimental to electronic performance so it minimizes or avoids reactivity with metals. The environment friendly process also results in cost saving because of decreased processing steps, lower consumables use and lower waste disposal costs. A drastic reduction in the corrosion rate can be obtained over traditional methods through the use of this acetic anhydride process
Applications for the Organic Contaminant Removal Technology
The technology for removing microscopic organic contaminants is currently used to remove organic material from substrates involved in semiconductor manufacturing and is equally applicable to such diverse industries as industrial processes, environmental engineering, medical devices and laboratory equipment. The wide range of other potential applications includes everything from flat panel displays to solar cell arrays.
Status of the Organic Contaminant Removal Technology
This organic contaminant removal technology is supported by U.S. patents. Technology support and expertise could be made available to assist the licensee in successfully deploying the technology.