Improved efficiency of CMOS light emitters in punch through with field oxide manipulation

Avalanche electroluminescence offers the opportunity for standard CMOS devices to be used as light emitters. Although inefficient, avalanche breakdown is inherently a fast process and potentially offers benefits in terms of speed when compared to emission based on forward biased junctions. Furthermore, the wide spectral characteristics of avalanche electroluminescence in the visible range also allows for some interesting applications. The main obstacle suppressing the use of these silicon light emitters in mainstream applications is inefficient radiative recombination. A number of techniques are known to improve quantum efficiency, one of which is operating the devices in punch through mode. This work focuses on improved results obtained from punch through devices, manipulation of the oxide above the radiative action and interesting results pertaining to the radiation pattern and the effects of LOCOS structures on the emission shape. This information could potentially benefit optical coupling to the light sources.