Fabrication Process for Electroabsorption Modulators

Abstract : This report focuses on the fabrication aspects of Electroabsorption Modulator (EAM) devices developed by the University of California at San Diego (UCSD). Air Force Research Laboratory (AFRL) SNDP personnel learned the processes directly at UCSD with the primary goal of transitioning the process to AFRL/SNDP. EAMs were designed to operate at 1550 nm using Indium Phosphide (InP) technology with semi-insulating wafers purchased from Tee Wel (Taiwan). Most of the process uses negative photoresist and is an 8-step mask procedure. The final metal coating is most critical to making robust n- and p- contacts. Without good metallization, wire bonding into a package fails. This report acts as a recipe aid to EAM device fabrication. Various times, levels, temperature, etc., quoted in this report were determined after careful calibration studies for each processing step and should only be used as guide values. Parameters change as materials age and machines change.