Formation of Ni silicide from Ni(Au) films on (111)Si

Abstract

Thermally induced transition metal contamination of silicide Schottky barriers on silicon AIP Conf.The solid state reaction between a Ni ͑7 at. % Au͒ film and a Si substrate at temperatures ranging from 250 to 800°C is examined by scanning electron microscopy, x-ray diffraction, and Rutherford backscattering spectrometry. Compared to the usual features for thin film reaction of Ni with Si, we observed the following. ͑i͒ The simultaneous growth of Ni 2 Si and NiSi, and the growth of NiSi at the expense of both Ni 2 Si and Ni. This is related to Au accumulation in the metal layer. ͑ii͒ Au precipitation at 300°C followed by the dissolution of the clusters thus created above the Au-Si eutectic temperature ͑370°C͒. ͑iii͒ A decrease of the temperature of formation of NiSi 2 and the appearance of thickness oscillations that are characteristic of nucleation. These different effects are interpreted by taking into account the metallurgy of the system: segregation of Au in the Ni film, Au solubility in the different silicides, change in surface and interface energies, and chemical interactions with Si.

Enhanced growth of CoSi2 thin films on (001)Si with Co/Au/Co sandwich structures

“…In previous studies, it has been demonstrated that the nucleation of metal silicides is significantly influenced by the presence of an interposing metal layer [6][7][8][9], a capping layer [10,11], and alloying elements [12][13][14][15]. For the formation of CoSi 2 thin films, recent studies have shown that the nucleation temperature of CoSi 2 was found to be dramatically lowered in the presence of small amounts of Au [8,16,17].…”

Ion beam induced mixing of co-sputtered Au–Ni films analyzed by Rutherford backscattering spectrometry

“…Due to improved electrical and chemical properties of the ion irradiated materials, mixing of metal-metal or metalsemiconductor systems using ion beam is frequently used to tailor different suitable contact materials for electronic devices [4,5]. Ion bombardment induced composite formation in Au-Ni bilayer or multiplayer films deposited on Si [6,7] or III-V nitride semiconductors [8] have been proved to be an effective method to fabricate contacts having low resistivity (typically, $ 6 Â 10 À4 V cm [9]). …”

Thermal evolution of the morphology of Ni/Ge(111)-c(2 × 8) surface

“…edu.tw No less attention is paid to the interaction of various atomic and molecular species with the surfaces. In particular, interaction of Ni with Si surfaces has attracted a considerable attention due to the richness of phenomena that occur at the interface, especially at elevated temperatures [4][5][6][7][8][9]. For example, trace amounts of Ni deposited onto the Si(111) can produce significant changes in surface reconstruction patterns, including the formation of the famous √ 19 × √ 19 superstructure as well as nano-sized islands of nickel silicides [9].…”