Optimization of thermal assisted direct bonding of soda-lime glasses for lab-on chip application

摘要

Surface treatment on glass before thermal assisted direct bonding (TADB) is an issue for lab-on chip fabrication. Surface cleaning for obtaining good quality TADB on soda-lime glass are studied and tested in this paper. The optimized cleaning solution for soda lime glass samples is NH₄OH–H₂O₂–H₂O (0.5:1:5 volume ratio) and it can be considered as the optimised solution for cleaning soda-lime glasses by this solution, as a result of a trade-off between cleaning efficiency and surface etching. The surface quality before and after cleaning is evaluated by optical microscopy, profilometry and atomic force microscopy. TADB between the cleaned samples is carried out and the bonding strength measured. The tensile strength of optimized samples after TADB was found to be higher than 15 MPa.