Диагностика неоднородности токораспределения в гребенчатых структурах мощных биполярных и гетеробиполярных транзисторов по рекомбинационному излучению

Abstract

A brief overview of methods for diagnosing current distribution and defects of high-power RF and microwave bipolar and heterobipolar transistors by recombination radiation is presented. An experimental setup is described for recording recombination radiation of structures of bipolar semiconductor devices with spatial resolution, which makes it possible to evaluate the inhomogeneity of current distribution in the comb structures of RF and microwave bipolar and heterobipolar transistors. The results of experimental testing of the installation on several samples of bipolar transistors of various types in the diode connection of the emitter junction are presented. It is established that the brightness of recombination radiation and, accordingly, the emitter current density monotonically decreases from the end to the base of the emitter tracks of current-carrying metallization, while the brightness inhomogeneity coefficient, defined as the ratio of the brightness of recombination radiation at the end to the beginning of the emitter tracks monotonically increases with increasing current flowing through the junction. An analytical model is proposed to explain the brightness distribution of recombination radiation along metallization paths in the comb structure of RF and microwave transistors.