Evaluation of the Self-Heating Effect in the Static Characterization of Cryo-Cooled Power Diodes

Designing cryogenically cooled power converters requires accurate models of semiconductor components at cryogenic temperatures. Such accuracy is impossible in the case of uncertainty with the effect of self-heating of parts at cryogenic temperatures, when self-heating can introduce a significant error into the results of static tests. Within the framework of this study, the main advantages and disadvantages of cryogenic cooling were analyzed from the point of view of temperature-dependent physical quantities of device materials that affect heat transfer processes inside the semiconductor structure. Using different test pulse durations and cooling methods, characteristics were obtained that allow one to judge the effect of self-heating on the static characteristics of diodes of various models. The obtained current-voltage characteristics at room temperature were compared with the characteristics from the manufacturer's documentation, and the methods of static characterization of power semiconductor devices were analyzed. In addition, the previously obtained results on the dynamic characteristics of the diodes were also evaluated.