Integrated hydrophilic surface treatment system of vapor deposition polymerization and vacuum ultraviolet irradiation for chemical/biochemical microchips

A novel system for hydrophilic surface treatment was developed. This system consists of a vapor deposition polymerization (VDP) unit for aromatic polyurea coating and a vacuum ultraviolet (VUV) irradiation unit for the hydrophilic treatment of the coated polyurea. Because the two vacuum chambers are connected by a load-lock system, a highly hydrophilic surface can be obtained without airborne molecular contamination (in situ process). The typical thickness of the polyurea film ranges from tens of nanometers to several micrometers. This system can be used for the high-throughput fabrication of chemical/biochemical microchips, which require a stable highly hydrophilic surface. The polyurea is made highly hydrophilic and a water contact angle of <20°is obtained. The surface free energy measurement and Fourier transform infrared (FT-IR) measurement results show that the degree of hydrophilic treatment is related to the VUV light intensity and the density of O₃ and exited oxygen atoms on the polyurea.