High speed, high reliability Si-based light emitters for optical interconnects

The barrier to the industrial implementation of optical interconnects on an IC, center around the fabrication of optical elements on wafers through conventional Si processes. It has been shown previously that Si-based p+-n+ diodes operating in avalanche breakdown mode emit light in the 400-900 nm range. This paper focuses on demonstrating that these Si-based light emitters can operate in the GHz range and provide reliable operation. The modulation of the light emitter was verified using a Hamamatsu streak camera for operation up to 50 psec of pulse width signals. The reliability of these emitters was verified through accelerated AC, DC, and temperature stressing. None of the stressing methods altered the total junction light emission. Low current DC stressing, however, did cause reversible light coalescence. A model has been developed to explain this phenomena.