Indium Bump Process for Low-Temperature Detectors and Readout.

We describe an indium bump process applicable to our low-temperature detectors and associated readout. A titanium nitride under bump metallization layer is reactively sputtered onto wiring pads as a diffusion barrier and adhesion layer. Indium is thermally evaporated onto this layer at the desired thickness for bump bonding. Patterning for both titanium nitride and indium layers is accomplished by liftoff techniques. The process flow is compatible with many processes utilized for the fabrication of low-temperature detectors and other superconductive devices. [ABSTRACT FROM AUTHOR]