Measurements of Avalanche Effects and Light Emission in Advanced Si and SiGe Bipolar Transistors

In this paper we present the first measurements of the light emitted by advanced npn bipolar transistors in the 1.1 - 2.7 eV energy range. Light emitted by recombination in the forward biased BE junction dominates the spectra in the low-energy, 1.1 - 1.3 eV region, while hot-electron-induced light emission in the collector region dominates for photon energies above 1.5 eV and markedly depends on the applied VCB. The distribution of the high energy photons is nearly maxwellian with equivalent temperatures ranging from 1500 K at VCB= 1.45V to 2700 K at VCB = 3.75V, furthermore their intensity results in a linear relationship with both the collector current and the avalanche-induced current.