Light-induced lifetime degradation in hydrogenated multicrystalline cast silicon substrates

Light-induced lifetime degradation in boron-doped p-type multicrystalline cast silicon (mc-Si) substrates has been studied with regard to lifetime distribution. The degraded lifetime was recovered by annealing at temperatures above approximately 200°C. The degradation observed is similar to that for low-resistivity boron-doped p-type Czochralski silicon (Cz-Si). The lifetime distribution of the degraded state becomes asymmetric due to the degradation in a high lifetime region. The light-induced lifetime degradation for mc-Si substrates is related to the substitutional boron and interstitial oxygen complex like that for Cz-Si. Hydrogenation is effective to reduce the content of the light-induced boron-oxygen complex and to suppress the light-induced lifetime degradation for mc-Si.