A study of the leakage mechanisms of silicided n sup + /p junctions.

Leakage mechanisms for shallow, silicided, n sup + /p junctions have been investigated. This study consists of two parts: (A) to isolate the processing steps that cause junction leakage, and (B) to study the mechanism for a particular process that causes leakage. Reactive ion etching, improper junction and silicide formation procedures, ion-mixing, and mechanical stress are found responsible for junction leakage, though through different mechanisms. Two mechanisms have been identified for junction leakage: (A) generation centers in the depletion region caused by deep levels from damage, or from impurities, and (B) Fowler-Nordheim tunneling caused by irregularities at the silicide/silicon interface at high reverse bias. Junction leakage can be avoided by carefully designing the details of silicide and junction formation and by carefully fine-tuning the processing steps to prevent damaging of the Si substrate after forming the junction.