DEEP ETCHED ZNSE-BASED NANOSTRUCTURES FOR FUTURE OPTOELECTRONIC APPLICATIONS

By electron beam lithography and a subsequent wet/dry etch process, optically active nanostructures are developed based on ZnSe with lateral extensions down to 35 nm. Dry etching using Ar+ ions is found to generate very smooth etch surfaces, while the photoluminescence efficiency of narrow wires is much higher in wet chemically etched structures. As a first application of deep etched nanostructures, index coupled distributed feedback laser structures of second order are realized with periods down to 185 nm on the base of (Cd, Zn)Se/ZnSe/(Mg, Zn)(Se, S) vertical waveguide heterostructures. A clear correlation between the resonator period and the emission wavelength is observed, indicating a high coupling coefficient of the structures. For optical pumping using a pulsed N-2-laser, the laser threshold at room temperature is about 100 kW/cm(2).