Electric field dependence of trap-assisted-tunneling current in strained SiGe source/drain junctions

Abstract

This paper evaluates the impact of the local electric field on the leakage current of strained Si1−xGex source/drain junctions. The difference in the SiGe and Si lattice constants creates a biaxial in-plane compressive stress in the epilayer and a tensile expansion on the top of the underlying silicon substrate. Current-voltage (I-V) and capacitance-voltage (C-V) measurements were employed to further investigate the stress-induced leakage current when field-assisted mechanisms such as trap-assisted-tunneling and band-to-band-tunneling are dominant, owing to the presence of high electric fields in the highly doped silicon depletion region.