Mesa-spacers: Enabling nondestructive measurement of surface energy in room temperature wafer bonding

In this paper, a way of measuring the surface energy of room-temperature wa fer bonding is presented. The method consists of introducing well-defined d efects. or "spacers," at the bond interface. Here SiO2 mesas were used as s pacers. From the resulting nonbonded area. around the spacers, the value of the surface energy is obtained. Results from surface energy measurements s how that there is good agreement between the "razor-blade" method and our " mesa-spacer" method. By using the mesa-spacer method, several of the proble ms associated with the razor-blade method are avoided. The method also allo ws the nondestructive measurement of the surface energy, which is interesti ng for applications in manufacturing of microsystems. (C) 2000 The Electroc hemical Society. S0013-4651(99)10-090-9. All rights reserved.