In order to increase the lifetime of the series contact MEMS switch with dielectric bridge
an isotropic undercutting process for forming the upper control electrodes and contact bar under the bridge is introduced. In comparison with the regular process
the introduced method can enhance the planeness of the bridge
avoid the problem of stress concentration
and thus improve the mechanical reliability of the switch. As a result
the yield rate of the switch increases from 10% up to 95%