A Low-Voltage Silicon Light Emitting Device in Standard Salicide CMOS Technology

A silicon-based field emission light emitting diode for low-voltage operation is fabricated in the standard 0.35 μm 2P4M salicide complementary metal-oxide-semiconductor (CMOS) technology. Partially overlapping p⁺ and n⁺ regions with a salicide block layer are employed in this device to constitute a heavily doped p⁺-n⁺ junction which has soft "knee" Zener breakdown characteristics, thus its working voltage can be reduced preferably below 5 V, and at the same time the power efficiency is improved. The spectra of this device are spread over 500 nm to 1000 nm with the main peak at about 722 nm and an obvious red shift of the spectra peak is observed with the increasing current through the device. During the emission process, field emission rather than avalanche process plays a major role. Differences between low-voltage Zener breakdown emission and high-voltage avalanche breakdown emission performance are observed and compared.