Wafer Transfer

Summary

Micro‐electro mechanical systems (MEMS) are used being combined with integrated circuit or large scale integration (LSI) in many cases. The heterogeneous integration can be performed by wafer transfer of multiple MEMS on a carrier wafer to an LSI wafer. The wafer transfer methods for the MEMS on LSI can be categorized as film transfer, device transfer (via‐last), and device transfer (via‐first). The heterogeneous integration using the wafer level transfer or the chip level wafer transfer can be used to fabricate key components for such systems. Lead zirconate titanate actuated MEMS switches were fabricated on an LSI wafer. The piezoelectric MEMS switch works at lower driving voltage and occupies smaller area than electrostatic MEMS switches. Digital fabrication of LSI based on maskless lithography is expected for cost‐effective small‐volume production and short‐term development. The MEMS wafer is bonded to a glass carrier wafer using bonding interlayer, and grooves are made on the MEMS wafer by dicing.