Optical and electrical properties of laser doped Si:B in the alloy range

We have probed the dopant activity of silicon B-doped by Gas Immersion Laser Doping (GILD). Here, we report on the comparison of optical, electrical and structural properties of Si:B, over a wide concentration range, up to 1.5 × 1021 cm−3 by steps of 1.5 × 1019 cm−3. Data obtained by reflectance FTIR spectroscopy are used within a Drude model to extract concentration, thickness and mobility. Resulting carrier concentration and conductivity are checked with 4-point probe electrical and X-ray diffraction measurements. FTIR proved to be very sensitive to the dopant distribution inside the layer, despite its thinness. It clearly reveals a moderate dopant accumulation at the interfaces.