Characterization of Plasma Induced Damage and Strain on InP Patterns and Their Impact on Luminescence

The effect of damage induced by plasma etching on the cathodoluminescence intensity of micron-size InP features is studied. At the etched bottom, it is found that the hard mask stripping process is sufficient to recover the luminescence. Within features, the presence of sidewalls reduces luminescence intensity due to additional non-radiative surface recombinations. For a n-doped sample, a carrier diffusion length of 0.84 μm and a reduced nonradiative surface recombination velocity of 2.58 are calculated. Hydrostatic strain within the etched features is measured using the peak shift of the luminescence signal, while in plane strain anisotropy is obtained from its degree of polarization, both with a resolution of about 100 nm.