Mechanism for Process-Induced Leakage in Shallow Silicided Junctions

Leakage mechanisms for shallow, silicided n+/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 mechanisms that cause 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: (A) generation centers in the depletion region caused by deep levels from damage, or from impurities, and (B) Fowler- Nordheim tunnelling caused by irregularities at the silicide/silicon interface at high reverse bias.