Defect-related luminescence and carrier transport in Ge-implanted SiO2 layers on n-Si and p-Si

Abstract

Ge ions of 100 keV were implanted into a 120 nm-thick SiO2 layer on n-Si at room temperature, 300, and 500 degrees C while those of 80 keV were implanted into a SiO2 layer on p-Si. Samples were subsequently annealed at 500 OC for 2 hours to obtain radiative defects from the implantation-induced non-radiative defects in the SiO2. The maximum intensities of sharp violet photoluminescence from the SiO2/n-Si and the SiO2/p-Si samples were observed for samples implanted with doses of 1x10(16) cm(-2) and 5x10(15) cm(-2), respectively. Besides the violet, a broad orange luminescence was seen in the hot-implanted samples. According to the current-voltage (I-V) characteristics, the samples with radiative defects exhibited leakage currents and electroluminescence only in the negative-bias region, regardless of the type of substrate.