Electrical characterization of low temperature plasma epitaxial Si grown on highly doped Si substrates

Epitaxial silicon layers were grown on highly doped c-Si substrates using the plasma-enhanced chemical vapour deposition process (PECVD) at low temperature (175 °C). The transport and defect-related properties of these epi-Si layers were characterized by current density-voltage (J-V) and capacitance-voltage (C-V) techniques. The results show that the epi-Si layers exhibit a non-intentional n-type doping with a low apparent doping density of about 2 × 1015 cm-3. The admittance spectroscopy technique is used to investigate the presence of deep-level defects in the structure. An energy level at 0.2 eV below the conduction band has been found with a density in the range of 1015 cm-3 which may explain the observed apparent doping profile.