HOT-CARRIER LUMINESCENCE IN SI

There has been a renewed interest in the spectra of emitted light from Si metal-oxide-semiconductor field-effect transistors (MOSFET's) in the belief that a better understanding of this phenomenon will lead to a deeper understanding of hot carriers in these devices. In this paper, we attempt to explain the physical mechanisms responsible for the light emission in Si under varying doping and carrier conditions and as a function of hot-carrier distribution functions. Based on this study, we have found that a proper inclusion of a realistic band structure is essential for the study of hot-carrier luminescence in Si. Furthermore, by including these band-structure effects, we conclude that the dominant light-emission mechanism in normally biased Si MOSFET's is a combination of direct and phonon-assisted inter-conduction-band radiation.