Suspended connection array for ultra low temperature applications

A silicon MEMS based component is projected and fabricated, that allows for minimum heat conductivity. while providing electrical connection on many channels by adopting an array of suspended superconducting metal lines, for ultra low temperature applications in the order of hundreds of microkelvin. The device is designed with L-Edit™ software and is fabricated at ITC-IRST microelectronics facility. The process has three mask levels and is divided into two splittings: one splitting is based on SU8 as polymer underlayer, the other uses polyimide. Bulk micromachining by anisotropic wet etching is used to create a cavity underneath the metal lines, and the dielectric layers underneath the lines are then dry etched leaving them suspended. The components are fabricated and technology issues related to the processing are investigated: self aligning of the polymer to the metal layer is examined to evaluate the undercut during plasma etching, and final release of the structure by silicon oxide removal is studied.