Wet rapid thermal oxidation of vertical cavity surface emitting laser structures with pyrogenic steam generator

In this article, the successful application of rapid thermal oxidation (RTO) with steam ambient for the selective oxidation of high aluminum containing embedded AlGaAs layer for the formation of current aperture in VCSELs is reported. The steam generation is achieved by the pyrogenic steam generation approach in which hydrogen and oxygen gas mixture is converted into steam by autoignition. Comparing to conventional furnace oxidation, steam-RTO showed a 6 times higher oxidation rate and an excellent oxidation uniformity across 4 inch wafers. It was also observed that after steam-RTO the Cr/Pt/Au p-type contacts had a 50% reduction in specific contact resistance compared to those oxidized in a conventional furnace