Effects of electromagnetic near-field stress on SiGe HBT’s reliability

In this paper, a reliability damage mechanism was presented in SiGe Heterojunction Bipolar Transistor (HBT). This new stress methodology differs from conventional SiGe, HBT device reliability associated with other stresses, since it was obtained by applying electromagnetic near-field aggression. The near-field set-up is used to disturb with electromagnetic field the Device Under test (DUT) on a localized area. Degradations in the base current and the current gain are identified. They are induced by a large base current leakage due to hot carrier which introduces generation/recombination trap centers at the silicon–oxide interface of the emitter–base spacer. By using the S-parameters measurements, we find that both forward transmission scattering parameter (S₂₁) and the input scattering parameter (S₁₁) are affected by this stress. In addition the power characteristics of DUT are also affected by stress. A Direct Power Injection (DPI) method is used to understand the near-field stress behaviour.