Characteristics of selective oxidation during the fabrication of vertical cavity surface emitting laser

Taking into account oxidation temperature, N₂ carrier gas flow, and thegeometry of the mesa structures this paper investigates the characteristics ofselective oxidation during the fabrication of the vertical cavity surface emittinglaser (VCSEL) in detail. Results show that the selective oxidation follows alaw which differs from any reported in the literature. Below 435℃selective oxidation of Al_0.98Ga_0.02As follows a linear growth law for thetwo mesa structures employed in VCSEL. Above 435℃ approximately increasingparabolic growth is found, which is influenced by the geometry of the mesastructures. Theoretical analysis on the difference between the two structures forthe initial oxidation has been performed, which demonstrates that the geometry ofthe mesa structures does influence on the growth rate of oxide at highertemperatures.