Controlled Oxide Vertical-Cavity Surface-Emitting Lasers with Lateral Oxidation Barriers

This proposal describes a fabrication-intensive program to determine the feasibility of fabricating oxide vertical-cavity surface-emitting lasers (oxide VCSELs) whose unoxidized current apertures comprise lateral oxidation barriers. Although oxide VCSELs have spectacular performances (50% wallplug efficiency, etc.) their manufacturability is questionable since the oxidation process forming the current aperture is highly sensitive to temperature, time and aluminum concentration. Furthermore, the oxidation processes may continue after fabrication, albeit at a slower rate, and degrade reliability. In contrast, the proposed VCSELs would have their current apertures defined by photolithography. Since the apertures comprise lateral oxidation barriers, the oxidation process is greatly suppressed within the apertures, enhancing reliability. The process employed to produce the lateral oxidation barriers has a wide, but reasonable, parameter space which requires some optimization in order to preserve the high performances of oxide VCSELs. This parameter space is best explored via experimentation rather than by calculations. Phase I will fabricate simple test structures with a wide range of the possible parameters, test them, and determine whether the process can produce practical oxide VCSELs. An optional task is to fabricate and characterize actual VCSELs using the proposed process.