Impact of damages in monocrystalline n‐Si on material photosensitivity

Abstract

The optical and electrical characteristics of p–n photodiodes based on monocrystalline n‐Si (wafers with ρ = 70 and 10 Ohm · cm and SOI) implanted with B+ in the dose range of 1 × 1014–1 × 1015 сm−2 and annealed at 900 °C (20 min) are studied. The p–n structures exhibit photosensitivity in the short‐wavelength infrared region (SWIR) with different maximum intensities depending on dose and n‐Si resistivity. Leakage currents are also dose‐dependent. The character of the SOI spectra is somewhat different. The optical and electrical properties of p–n photodiodes are described in terms of formation of extended defects with deep levels in the bandgap appearing after B implantation and annealing of n‐Si. The importance of the damaged surface layer in the starting material for the observed effects is confirmed experimentally. The relation of the SWIR photoresponse intensity to the content of C and O gettered to the p–n structure surface is revealed. The innovative aspects of technology application are discussed.