Composition Control of Ni Silicide by Chemical Vapor Deposition Using Ni(PF₃)₄ and Si₃H₈

Abstract

Ni silicide film was deposited by chemical vapor deposition (CVD) using an Ni(PF3)4/Si3H8 gas system. Ni(PF3)4 has no carbon atoms in its molecules and has sufficiently high vapor pressure for a mass flow controller to be used. We selected Si3H8 as the silicon precursor, which was decomposed by the interaction of a metalorganic Ni precursor at a low temperature at which thermal decomposition could not occur. Using these precursors, Ni silicide film was deposited at low temperatures (∼160 °C). The deposited Ni silicide film was polycrystalline and had low crystallinity. Ni2Si and Ni5Si2 were also formed. Varying the Si3H8 flow rate and substrate temperature changed the Si/Ni ratio of the films resulting in the flat-band voltage (Vfb) for the Ni silicide electrode shifting with the Si/Ni ratio. This CVD-deposited Ni silicide should be able to be applied to the fabrication of metal gate in future metal oxide semiconductor field-effect transistors (MOSFETs).

Self-formation of dielectric layer containing CoSi2 nanocrystals by plasma-enhanced atomic layer deposition

“…For example, WSi 2 is deposited by chemical vapor deposition (CVD) from WF 6 and SiH 4 for gate electrode in memory device fabrication [10]. However, the direct deposition of transition metal silicides such as Co or Ni silicide has been rarely reported [11,12]. Also, high temperature over 600 1C and toxic precursor are required for this process.…”

Chemical Vapor Deposition Pt-Ni alloy Using Pt(PF3)4 and Ni(PF3)4

“…On the other hand, chemical vapor deposition (CVD) is an attractive technique for metal gate formation because of its good controllability of the film composition and its excellent step coverage. We have previously proposed tetrakis(trifluorophosphine)nickel (0);Ni(PF 3 ) 4 as a Ni-CVD precursor and deposited Ni and Ni-silicide films with a good step coverage quality [5][6]. We, also reported tetrakis(trifluorophosphine)platinum (0); Pt(PF 3 ) 4 as a Pt precursor, which has the same ligand as Ni(PF 3 ) 4 .…”