Laser etching of 0.4 μm structures in CdTe by dynamic light guiding

Abstract
CdTe single crystals have been etched by photosublimation with a cw visible laser. Structures with lateral widths comparable to the laser wavelength (∼0.5 μm) and depths exceeding 10 μm were obtained using a moderately focused beam. The formation of these structures is highly nonlinear with respect to laser power and is analyzed in terms of the dynamic interaction of the beam with the induced microstructure. Once initiated, deep structures are formed via laser-induced tellurium enrichment of CdTe surface layers and the consequent enhanced waveguiding properties of these surfaces. The mechanism of etching has been studied by mass spectrometer and light scattering experiments.