Cryogenic electronics plays a fundamental role in several applications, such as spacecraft, high-energy physics experiments, metrology, superconductive astronomical detectors and, with the increased interest in quantum computing, the manipulation of quantum bits (qubits) [1]. Outstanding characteristics have been reported for advanced CMOS technologies operating at cryogenic temperature in terms of on-state current, leakage current, subthreshold swing, and transconductance [2]. This represents an excellent opportunity to use such advanced technologies to design and implement a quantum computing control system (including multiplexers, LNAs, and RF oscillators) and introduce it inside the refrigerator together with the qubits [3]. Another recently growing field of application is the cryogenic silicon photonics [4].

Gallium Nitride High Electron Mobility (GaN HEMT) device technology has gained a lot of traction during the last years. These devices have significant advantages compared to Silicon in user applications such as high frequency/high power amplifiers, radar systems, power conversion and applications where stability over a wide range of temperatures is required, such as automotive-related.

It is often the case, that an Engineer is required to simulate environmental effects on a device manufactured by a third party.  In such an event, the first issue that is faced by the Engineer, is a lack of access to the manufacturing process that created the third party device in the first place.  In this article, it is shown how to overcome this first issue, and reverse engineer a sufficiently representative base device, simply from the manufacturer’s specification sheet.  Once a satisfactory device has been fabricated, it can be used in the required simulation to analyze any effects of interest.  In this particular case, we will demonstrate the damaging effects of irradiating a 2N2222A bipolar transistor with a proton flux and compare the simulated results with other similar measured results.