Selective Surface Modification Using Amine Chemistry for Enhanced Semiconductor Cleaning Performance
Huntsman is one of the world’s largest producers of amine chemistry with over 20 years of experience in servicing the high purity and quality needs of the semiconductor industry. Our E-GRADE® amines have been used in formulations of advanced cleaning chemistries. These formulated cleans are critical to the semiconductor industry and are growing in importance for advanced nodes due to the increasing demands for higher performance cleans. The surface properties of semiconductor materials are key throughout each step in the IC process. In this case study, we investigated the possibilities of modifying various substrates via selective amine chemistry, with use of three groups of chemicals: amines, quaternary ammonium compound, and amine N-oxides.
We examined interactions between amine and silicon, silicon nitride, silicon oxide, and organic materials. It was found that amines may readily form chemical bonds or electrostatic interactions with the target surfaces and change their properties (e.g., zeta-potential, hydrophilicity, etc.); the amines can also protonate and generate hydroxide ions, which promotes the hydrolysis and removal of certain materials.
Quaternary ammonium compounds and their interactions on silicon, Si3N4, and SiO2 were studied. The variations in molecular structures led to different alkalinity/hydroxide ions’ activity, etch rate, as well as final surface textures and hydrophilicity.
The amine N-oxides demonstrated good control and selectivity on silicon and metal etch under various conditions, The amine N-oxides is a group of compounds of strong polarity due to their unique N+ ‒ O- dative bond 3. They are mild organic oxidants compatible with acid, base, and oxidant (like H2O2).
In conclusion, a range of amines, quaternary ammonium compounds, and amine N-oxides from the Huntsman E-GRADE® product lines were found to successfully modify various materials’ surfaces. The selected products exhibit excellent versatility and can be incorporated into a range of aqueous formulations and provide the benefits of a wetting agent, etch promoter/inhibitor, etc.
BIOGRAPHY
Hui Zhou has a PhD degree in Polymer Chemistry and Physics from Fudan University. He joined Huntsman in 2010. He has worked in the chemical industry for around 20 years and has broad experience in coatings and composites. Most recent eight years he is focusing on development of new electronic grade of specialty amines and solvents used in semiconductor industry for etching, stripping and cleaning applications. He has been granted eight US Patents.