An efficient low voltage, high frequency silicon CMOS light emitting device and electro-optical interface

A silicon light emitting device was designed and realized utilizing a standard 2-mu m industrial CMOS technology design and processing procedure. The device and its associated driving circuitry were integrated in a CMOS integrated circuit and can interface with a multimode optical fiber. The device delivers 8 nW of optical power (450-850 nm wavelength) per 20-mu m diameter of chip area at 4.0 V and 5 mA. The device emits light by means of a surface assisted Zener breakdown process that occurs laterally between concentrically arranged highly doped n(+) rings and a pf centroid, which are all coplanarly arranged with an optically transparent Si-SiO2 interface, Theoretical and experimental determinations with capacitances and series resistances indicate that the device has an intrinsic high-frequency operating capability into the near gigahertz range.