  Semiconductor integrated circuits operated at cryogenic temperature will play
an essential role in quantum computing architectures. These can offer
equivalent or superior performance to their room-temperature counterparts while
enabling a scaling up of the total number of qubits under control. Silicon
integrated circuits can be operated at a temperature stage of a cryogenic
system where cooling power is sufficient ($\sim$3.5+ K) to allow for analog
signal chain components (e.g. amplifiers and mixers), local signal synthesis,
signal digitization, and control logic. A critical stage in cryo-electronics
development is the characterization of individual transistor devices in a
particular technology node at cryogenic temperatures. This data enables the
creation of a process design kit (PDK) to model devices and simulate integrated
circuits operating well below the minimum standard temperature ranges covered
by foundry-released models (e.g. -55 {\deg}C). Here, an efficient approach to
the characterization of large numbers of components at cryogenic temperature is
reported. We developed a system to perform DC measurements with Kelvin sense of
individual transistors at 4.2 K using integrated on-die multiplexers, enabling
bulk characterization of thousands of devices with no physical change to the
measurement setup.
