Design and fabrication of VCSEL's with AlxOy-GaAs DBR's

A procedure for fabricating vertical-cavity surface-emitting lasers (VCSEL's) with oxide-based distributed Bragg reflectors (DBR's) is presented. An in-depth analysis of parameters and behavior unique to oxide VCSEL's determines the device design. The development cycle time for these devices is reduced through development of a method for post-growth analysis of the epitaxial stack reflectivity before device processing. Threshold currents as low as 160 mu A and resistances as low as 80 Omega are demonstrated using different device designs. The total optical loss of low-doped oxide VCSEL structures is 0.163% which is comparable to VCSEL designs based on all-semiconductor DBR's. The thermal resistance of an 8 x 8 mu m VCSEL is measured to be 2.8 degrees C/mW, demonstrating that the presence of oxide layers does not act as a barrier to heat flow out of the active region.