The Features of Infrared Absorption of Boron‐Doped Silicon

Abstract

Herein, the influence of heat treatment at 400 °C on the spectrum of boron intracenter transitions in silicon using IR absorption spectroscopy is investigated. In the transition region from the ground 1Γ8+ state associated with the p3/2 valence band of Si to the odd‐parity excited states of boron, a new absorption line with its maximum at 261.3 cm−1 is observed in the thermally treated boron‐doped Cz‐Si. Oxygen is a component of defect that is responsible for the detected absorption line. Perturbation of boron atoms due to the inhomogeneous stress effect from neighboring oxygen atoms results in a frequency shift in the main boron transition. The defect associated with 261.3 cm−1 line is also observed in as‐grown silicon. The defect disappears during annealing at 550 °C. The concentration of defects and binding energy of the 1Γ8+ ground state are estimated assuming that the line observed belongs to the transition of boron 1Γ8+ → 2Γ8−, subjected to the perturbation from a neighboring oxygen atom.