Effects of capping layers on the electrical characteristics of nickel silicided junctions

✍ Scribed by Chi-Chang Wu; Wen-Fa Wu; P.Y. Su; L.J. Chen; Fu-Hsiang Ko

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 621 KB
• Volume: 84
• Category: Article
• ISSN: 0167-9317
• DOI: 10.1016/j.mee.2007.01.198

✦ Synopsis

In this paper, effects of capping layers on formation and electrical properties of Ni-silicided junctions have been investigated. Nickel silicide films using the Ti or TiN-capped layer process are used to compare to those by the uncapped process. The uncapped (Ni single layer) and TiN-capped samples are shown to exhibit better thermal stability than the Ti-capped samples. For the silicided junctions, samples using Ti capping layer processes exhibit larger leakage current densities. A high-resistivity Ni x Ti y Si z compound layer is formed on the surface during silicidation for the Ti-capped sample, while the uncapped and TiN-capped samples are not. In addition, it is found that the thickness of NiSi layer, as well as the Ni x Ti y Si z layer, increases with increasing the Ti capping layer thickness. The formation of Ni x- Ti y Si z layer not only increases the contact resistance, but also deepens the silicide thickness.