High-yield, reliable electrically pumped index-guided vertical cavity
lasers with diameters less than 4 microns have been fabricated using l
ow resistance, alloyed, ring contact metalization. Existing metallizat
ion schemes used for bottom emitting vertical cavity lasers (VCLs) ten
d to be highly resistive, since the top metallization layer serves the
dual purpose of mirror and electrical contact. This results in accept
able performance for large diameter devices, but poor performance for
smaller devices that operate at higher current densities. Low resistan
ce alloyed ring contacts have been developed for small bottom emitting
VCLs that maintain the required optical properties while dramatically
improving the electrical properties.