Quantum computing will likely utilize numerous new technologies which operate at different cryogenic temperatures. For example, a quantum computer might deploy CMOS memory modules at 77K, superconducting control chips at 4K, and a quantum processing unit (QPU) at less than 20 mK. To develop and deploy these various subsystems and technologies, it is vital to reliably and efficiently test and measure them at or near their operating temperatures.
Wafer probing has been done for some time in waveguide at frequencies up to several hundreds of GHz. However solutions were typically limited by the constraints of large format extenders with large format positioners, which could limit the capabilities for over temperature work or RF performance.
Recent advances from Virginia Diodes Inc. and Formfactor, have allowed for solutions that allow optimal path lengths and the ability to isolate the extenders from elevated thermal temperatures while still also carrying out cold / dry / dark measurements.