A Flexible Fabrication Process for Thin Si-Substrate chips on Millimeter Wave Applications

A flexible process for fabricating thin Si-substrate chips, implemented in millimeter-wave waveguide devices, had been developed. The geometry of chip was accurately defined by a deep Si-etch process. The thickness accuracy of Si-substrate is better than 2 micrometers by performing the backside lapping and then the dry etch processes. Two thin Si-substrate millimeter wave chips with substrate thickness of 20 micrometers are presented as examples.