Piezoelectric reliable RF-MEMS switch with narrow contact-gap using wafer-bond packaging

This paper presents a low-cost packaged and reliable piezoelectric-actuated RF-MEMS switch for mobile communications. We fabricated a stiff single crystal silicon (SCS) beam that has an actuator and a contact bump on an SOI wafer without backside etching. We bonded the wafer to a ceramic cap wafer, directly packaging a switch with a contact gap of 0.5-μm not using sacrificial layers. The switch operated up to 1 billion cycles keeping a low insertion loss (<;0.4 dB up to 5GHz) at 20-V driving voltage. The surface mountable SPST switch was 1.6 × 1.1 × 0.8 mm in size.