A 128 × 96 pixel CMOS microdisplay utilizing hot carrier electroluminescence from junctions in reach through

Abstract

Visible light from silicon junctions under avalanche breakdown can be used to create microdisplay systems with integrated light sources. Junctions available in standard CMOS usually breaks down at much larger voltages than the typical operating voltage for integrated circuitry. It is possible to reduce the operating voltage of by making use of techniques which changes the electric field profile in light sources based on hot carrier electroluminescence such as electric field reach through between two highly doped implant regions. This work successfully demonstrates the possibility of tailoring the operating voltage and quantifying the optical performance in an integrated microdisplay consisting of a 128 by 96 pixel array based on light sources in standard CMOS. Based on the approach followed it becomes possible to integrate light sources in such a manner that it can coexist and interact with other on-chip analog and digital circuitry. The requirements for architectural features of a microdisplay in standard CMOS is discussed and it is shown to be possible to create large scale integrated circuits containing integrated light sources in standard CMOS without the need for postprocessing or additional back end modifications.