Light‐Induced Degradation in Annealed and Electron Irradiated Silicon

Abstract

The composition of the defect, which is responsible for the boron–oxygen‐related light‐induced degradation (BO‐LID) of the carrier lifetime in silicon, still remains an unresolved issue. It has been recently suggested that the BO‐LID is due to the ASi‐Sii‐defect. Within this idea, the creation and discreation are governed by the interstitial silicon concentration. Annealing and electron beam (EB) irradiation are applied to influence the interstitial silicon concentration. The BO‐LID is observed in the case of diffusion‐oxygenated FZ (DOFZ) boron‐doped silicon after annealing at 650 and 450 °C for 4 h, respectively. A nearly complete discreation of the BO‐LID defect is found for the long‐term high temperature (16 h at 1050 °C) anneal. This discreation process is explained by the diffusion of the interstitial silicon atoms to other sinks such as the wafer surfaces. The degradation of the carrier lifetime due to illumination after the EB irradiation is unambiguously related to the BO‐LID phenomenon.

The ASi–Sii Defect Model of Light‐Induced Degradation (LID) in Silicon: A Discussion and Review

“…It should be noted that the creation of LID was found in diffusion‐oxygenated FZ (DOFZ) silicon wafers treated at 650 °C. [ 50 ] Obviously, further carefully designed experiments are necessary which include the solar cell fabrication process or layer deposition processes to finally prove the impact of silicon self‐interstitials on the LID. At present, an A Si –Si i defect can neither be ruled out, nor be proven by existing experimental data.…”

“…It should be noted that the creation of LID was found in diffusion-oxygenated FZ (DOFZ) silicon wafers treated at 650 °C. [50] Obviously, further carefully designed experiments are necessary which include the solar cell fabrication process Comparison of normalized LID defect concentration [30] and precipitated oxygen concentration after annealing steps [37,38] as a function of interstitial oxygen concentration (see text). within the LDA approximation using the VASP code, [48] illustrated using the VESTA software: [49] Different charge states of the defect are accompanied by minor local adjustments of the ion positions.…”