July 16, 2009 – IMEC had several major announcements at SEMICON West. Ludo Deferm discusses the major advantage of using laser anneal over spike anneal: the reduced thermal budget. The low budget limits the diffusion of dopants into the silicon during their activation. Such a limited diffusion helps to keep short channel effects under control as the physical dimensions of the transistors shrink.
Deferm also summarizes the research center’s EUV mask cleaning program. The research will develop processes of record (PORs) for EUV mask cleaning that are effective in removing the contamination of interest, yet are gentle enough to be applied repeatedly without reducing mask lifetime.
IMEC researchers have also investigated RuTa metallization as a promising scheme for achieving good metallization of 22nm features. It could likely replace the traditional Ta physical vapor deposition (PVD), which, for decreasing feature sizes, looses its ability to achieve uniform Cu seed. The research center evaluated four different metallization schemes (i.e., TaN/Ta, RuTa, TaN + Co and MnOx) in terms of Cu fill, electrical performance and compatibility with chemical mechanical polishing (CMP) slurries.