High-energy He-ion irradiation-induced defects and their influence on the noise behavior of Pd/n-Si1-xGex Schottky junctions

We report on the electrical properties of defects introduced by high-energy 5.4 MeV He ions in n-type strained n-SiGe and the impact of this irradiati on on the noise properties of Pd/n-Si1-xGex Schottky barrier diodes (SBDs). From the deep level transient spectroscopy measurements, the main defects EA1 and EA2 are observed in both Si and Si0.96Ge0.04 and have energy levels at 0.24 and 0.44 eV, respectively, below the conduction band. EA1 and EA2 have been correlated with the V-V and the P-V pairs, respectively. For both defects EA1 and EA2, the energy level position is found to be the same for x = 0 and 0.04, indicating that such levels are pinned to the conduction b and. Furthermore, the impact of the high-energy He-ion irradiation on the e lectrical noise properties of Pd/n-Si1-xGex SBDs is also studied. From the noise experimental data, the main noise source observed in these irradiated diodes was attributed to the generation-recombination noise inducing an ab normal peak in their noise spectra at around f(1) = 180 Hz. This peak is fo und to be independent of Ge concentration. (C) 2000 American Institute of P hysics. [S0003-6951(00)02125-2].