Platinumsilicide Schottky barrier infrared detectors with a grating: Dependence of the optical response on wavelength and polarization

Abstract

Platinumsilicide Schottky diodes on p-Si substrates structured with a dry-etched lamellar grating were fabricated. The grating periods Λ were 3, 4, and 5 μm, and the grating amplitude h ranged from 300 to 1100 nm. Measurements of the optical response Y for TE and TM polarized light were made. A strong dependence of the detector sensitivity on the polarization of the radiation was observed. Enchancement of the responsivity up to 70% was found compared to an unstructured reference sample. Calculations based on an optical model which takes into account the change in absorption due to the grating were made. The results show good agreement with the experimental data.