On-wafer testing of monolithic microwave integrated circuits (MMICs) plays an increasingly important role in the design and manufacture of circuits and products widely used in the telecom and defence industries.
The present method of testing of MMICs is based on the use of microwave contacting-probes, aligned on to pre-defined contact pads on the semiconductor wafer by means of a precision test-jig. Measurements are limited by the available probes to about 40 GHz and by the requirement for contact pads at every circuit node of interest. The trend towards denser integration of devices and higher operating frequencies is exposing the limitations of this method.
The objectives of this project are the development of a new electro-optic sampling (EOS) technique for the testing of MMICs on the wafer (before dice and mount) together with its implementation into a commercial instrument, capable of extending the measurements to packing densities and frequencies higher than possible with conventional methods. The EOS technique is based on in situ measurements of the electric field due to a signal propagating within the circuit, without test pads.
Funding SchemeCSC - Cost-sharing contracts