Electrical characterization of {311} defects and related junction leakage currents in n-type Si after ion implantation

Abstract

A special fabrication process involving chemical vapor deposition (CVD) was designed in order to fabricate advanced structures used to successfully investigate both deep level transient spectroscopy (DLTS) and leakage currents related to the defects on the same test structures. Silicon ions of energy 160 keV and doses 1.0 × 1012 cm−2, 1.0 × 1013 cm−2 and 8.0 × 1013 cm−2 have been implanted into n-type Si substrate and annealed at 800°C. The highest dose was specifically used to create rod-like {311} extended defects. DLTS spectra show prominent electron traps at EC - 0.26 eV, EC - 0.46 eV and EC - 0.54 eV. There were no observable deep levels in the un-implanted (reference) samples. The identity and origin of all these traps will be interpreted in conjunction with annealing studies, literature results and recently developed predictive defect simulation models. The junction leakage current is found to slightly increase in the presence of {311} defects, which shows that their presence does not significantly increase junction leakage currents in n-type silicon.