Silicidation in Ni-Si System
Silicide formation induced by thermal annealing in Ni/Si thin film system has been investigated using glancing incidence X-ray diffraction. Silicide formation takes place at 600degC with Ni2Si, NiSi and NiSi2 phases co-existing with Ni. Complete conversion of intermediate silicide phases to the final NiSi2 phase takes place at 900degC. A comparison of the experimental results in terms of annealing temperature, Ni thickness, and dopant impurities with Ni-Si phases is presented. Nickel silicide (NiSi) is emerging to be the choice material for contact application in semiconductor device processing for sub_65 nm technology node and beyond. The focus of present work is to facilitate better understanding of the influence of thermal budget on nickel silicide solid-state reaction. Requirements for low temperature anneal and improving within wafer sheet resistance uniformity pose challenges for conventional lamp-based rapid thermal processing (RTP) due to lamp response effects on temperature controllability. Evolution of the nickel-rich silicide phase as a function of temperature is recorded using X-ray diffraction (XRD) techniques. It is postulated that lowering the Ni2Si/Si interface energy favors the delay of the agglomeration of the NiSi.
Applications of Ni-based silicides to 45 nm CMOS and beyond
This paper presents an overview of Ni-alloy (Ni, Ni-Pt and Ni-Ta) silicide development for the 45 nm node and beyond, including applications to self-aligned silicide (SALICIDE) processes, reaction with SiGe and strained Si on SiGe, and applications to fully silicided (FUSI) gates. Key SALICIDE issues addressed include the use of spike or low temperature rapid thermal processes (RTP) to control silicidation and junction leakage on small features, factors affecting the formation of epitaxial pyramidal NiSi 2 grains, and NiSi thermal stability and agglomeration kinetics. Alloying with Pt or Ta is shown to improve thermal stability of NiSi films, although with quite different behaviors. While Pt is incorporated predominantly in solution in NiSi, Ta segregates to the surface of the films. Ni-Pt alloy silicides were also found to achieve low sheet resistance on narrow gates, low contact resistivity and low junction leakage, making them attractive for CMOS applications. For the Ni/SiGe reaction, a narrower RTP process window for low sheet resistance and a lower activation energy for agglomeration were observed when compared to the Ni/Si reaction. The lower thermal stability was correlated to Ge segregation from the Ni(SiGe) films. The Ni/doped poly-Si reaction was studied for FUSI gate applications, showing a retardation of the silicidation kinetics for high B doses and a large pile- up of dopants (for As, B or P) at the NiSi/SiO 2 interface due to dopant snowplow during silicidation. The work function (WF) of NiSi was observed to shift with the addition of dopants, effect attributed to modifications of the interface dipole by the pile-up of dopants. No significant degradation was observed when comparing gate oxide breakdown statistics for Ni FUSI to conventional poly-Si gates. The process window for a FUSI gate-last process (performed after S/D Ni silicidation) was evaluated showing a potential integration problem due to possible degradation of the S/D silicide during the FUSI gate reaction.
The politics of affect and emotion in contemporary Latin American cinema : Argentina, Brazil, Cuba, and Mexico
Between Neo-realist Sentimentality and Modernist Shock: New Latin American Cinema and Beyond Thrilling Histories: Questions of Genre and History Affecting Legacies: Contemporary Structures of Feeling Alien/Nation: Contemporary Youth in Film Emotional Investments: Global Networks and Transnational Affective Communities