Defect levels in H+-, D+-, and He+-bombarded silicon

Defect levels produced by H+, D+, and He+ bombardment of silicon with different phosphorus doping and oxygen content were investigated using transient capacitance spectroscopy. After He+ implantation only pure damage defect levels occur, whereas after H+ and D+ implantation additional hydrogen-related defects are observed. For vacancy-related defects both the peak concentration and the halfwidth of the profiles depend only on the Fermi energy. The profiles were found to be broader than the theoretical vacancy distribution. The broadening which increases with decreasing doping level is explained by a model based on electric-field-enhanced diffusion. The production behavior of the defects shows a linear dependence of the sheet concentration on the ion dose for vacancy-related defects and a quadratic dependence for the hydrogen related defect E(0.30). This defect is tentatively identified as the (H-V) pair.