Luminescence spectroscopy of dry etched single dots and wires

Abstract

Using spatially resolved luminescence spectroscopy we have measured the luminescence properties of single dry etched InP/InGaAs wires and dots. For fabrication of the test structures single quantum well samples grown by metalorganic vapor phase epitaxy were structured by e-beam lithography and subsequent dry etched with CH4, H2, and Ar at different bias voltages. The lateral dimensions of the wires and dots ranged from 10 μm down to 70 nm. The smallest structures that could be measured at room temperature and without surface passivation were 70 nm for wires and 100 nm for dots. By spatially resolved intensity scanning of mesa structures a characteristic intensity profile could be observed. Due to the inhomogeneous excitation and diffusion effects, a significant enhancement of the luminescence on the edges and corners of the structures can be seen even for nonovergrown samples.