Transition-metal silicides formed by ion mixing and by thermal annealing: Which species moves?

Abstract

The moving species during the formation of Pt2Si, Ni2Si, and CrSi2 by both ion mixing with 300–600 keV Xe ions and thermal annealing is identified with inert markers using backscattering spectrometry. Samples of metal-on-silicon and silicon-on-metal have been used, evaporated on SiO2 substrates with two very thin markers (Mo for Pt2Si, W for Ni2Si and CrSi2) placed at the metal–silicon interface, and at the bottom interface with the SiO2 substrate. Monitoring the separation of the two markers as a function of the amount of silicide formed determines the ratio of atomic transport through the growing silicide layer. The results establish that the dominant moving species in both silicide formation processes is the same for the refractory metal-silicide CrSi2, e.g., Si, whereas different atomic transport ratios are found in the case of the near-noble metal silicides Pt2Si and Ni2Si. This outcome is discussed in terms of high-temperature effects during thermal formation of transition-metal silicides.

Ion-Beam Mixing in Layered Systems

“…В процессах ионно-лучевого и термического фазообразования много общих особенностей. Установлено, что первая фаза, образующаяся на межфазных границах раздела в слоистых системах металл-кремний, при обоих типах воздействия одна и та же [16][17][18]. Наиболее подвижными компонентами являются те же атомы, что и при термическом отжиге.…”

“…Наиболее подвижными компонентами являются те же атомы, что и при термическом отжиге. Например, в системе Mo-Si атомы кремния являются наиболее подвижными частицами при обоих типах воздействия [18]. Но имеются существенные особенности фазообразования при ионно-лучевом воздействии.…”

Assessing the degradation mechanisms and current limitation design rules of SiCr-based thin-film resistors in integrated circuits

“…SiCr-based materials meet these criteria and are therefore attractive alternatives to poly-silicon for integrated thin-film resistors in RF technologies. Despite many investigations carried out on SiCr-based materials in material sciences [2][3][4][5][6][7][8][9], information on reliability of SiCr-based integrated thin-film resistors in IC processes has rarely been reported. In the work of Brynsvold et al [10] intensive investigations are carried out on the "wear-out" of SiCr-based resistors under current and temperature stress in their process technology.…”

The determination of dominant diffusing species in the growth of amorphous interlayer between Gd and Si thin films by a Mo cluster marker experiment

“…8,9 Implanted gas bubbles, 9,10 radioactive tracers, 11,12 and an inert layer have been used as markers. In the present study, the diffusion process in the formation of an a-interlayer in the Gd/Si system using embedded Mo clusters as markers has been investigated by transmission electron microscopy and energy dispersive x-ray as well as autocorrelation function analysis.…”

“…For the barrier effect, the marker between two reacting elements acts as a barrier, resulting in a higher starting reaction temperature and/or a lower rate. [8][9][10]14,15 The diffusion marker technique adopted in the present study was to place inert clusters in the a-interlayer instead of a continuous planar marker. Since the diffusivities of the marker material in the thin films of the reacting elements with polycrystalline structures are usually unavailable, the ideal choice would be the marker that has the lowest mutual solubilities with the two reacting elements.…”