Glass-to-glass electrostatic bonding with intermediate amorphous silicon film for vacuum packaging of microelectronics and its application

In this work, we have developed a new high vacuum packaging method using a glass-to-glass bonding with an intermediate amorphous silicon (a-Si) film for the application to microelectronic devices such as field emission display and plasma display panel. The glass-to-glass electrostatic bonding was established and optimized by introducing thin amorphous silicon interlayer. Also, we propose that the amount of oxygen ions is one of the important factors during the bonding process, as confirmed from the SIMS and XPS analyses for the reaction region of Si-O bond in interface. Our method was very effective to reduce the bonding temperature and make the high vacuum package of microelectronic devices over 10^-4 Torr. Finally, to evaluate the vacuum sealing capability of devices packaged by the method, the leak characteristics of the vacuum was examined by a spinning rotor gauge during 6 months. The electron emission properties of the field emission display and plasma display panel were measured continuously for time variation.