Band bending at the Si(1 0 0)–Si3N4 interface studied by photoreflectance spectroscopy

Photoreflectance spectroscopy has been used to measure the band bending at the p-Si(1 0 0)–Si3N4 interface subjected to annealing and ion implantation. Upon annealing, unimplanted interfaces exhibit a constant band bending of about 0.77 eV, even though the spectral amplitude changes due to variations in the way minority carriers are annihilated at the interface. Implantation reduces the band banding, although subsequent annealing in stages up to 900 °C progressively restores the bending to its original value through pathways exhibiting a wide range of activation barriers.