Schottky barrier height tuning of silicide on Si1−xCx

Abstract

We have demonstrated the tuning of Schottky barrier height (SBH) of nickel silicide on silicon-carbon (Si1−xCx) by varying the carbon mole fraction, x. The SBH (for electron conduction) has been found to decrease with carbon concentration at a rate of ∼6.6meV/ (0.1% carbon). We have achieved ∼27meV drop in SBH with 0.4% carbon incorporation in Si1−xCx and shown that 1.3% carbon could lead to more than 85meV improvement. Furthermore, our results show an avenue to reduce the SBH of rare earth silicide contacts in n-channel Schottky transistors by fabricating them on Si1−xCx.

Schottky Barrier Height of Nickel Silicide Contacts Formed on $\hbox{Si}_{1 - x}\hbox{C}_{x}$ Epitaxial Layers

“…Another possibility might be the presence of a spatially inhomogeneous Schottky barrier as proposed by Tung et al [13] for NiSi 2 , which may cause the effective barrier height to change with doping type and density. It is important to note that, regardless of the extraction method, the electron barrier-height reduction observed in this letter is much larger than the reduction predicted by Sinha et al [7], who suggested a barrier-height reduction of 65 meV per 1% C by linear extrapolation of their experimental data which were limited to a maximum carbon concentration of 0.4%. They concluded that the reduction in the electron barrier height could be explained solely by the reduction in the Si 1−x C x bandgap, which implicitly suggests that the metal Fermi level is pinned at a fixed position relative to the valence band.…”

“…These reports mainly focused on Manuscript formation and the structural properties of NiSi 1−y C y layers. Sinha et al [7] measured the electron barrier height at the NiSi 1−y C y /Si 1−x C x interface up to a limited carbon concentration of 0.4%. It was shown that the electron barrier height was reduced by 27 meV as a result of carbon incorporation in the underlying Si layer.…”

Schottky Barrier Height of Erbium Silicide on $ \hbox{Si}_{1 - x}\hbox{C}_{x}$

“…Regardless of the device application, there will be a need to form high-quality ohmic or rectifying contacts to Si 1−x C x alloys. The results from several studies on this topic have been published in several recent articles [10]- [14]. These studies, which mainly focused on NiSi contacts, demonstrated that C incorporation improved the thermal stability of the silicide, while it resulted in a silicide with slightly higher resistivity.…”

“…These studies, which mainly focused on NiSi contacts, demonstrated that C incorporation improved the thermal stability of the silicide, while it resulted in a silicide with slightly higher resistivity. The Schottky barrier height, φ B of NiSi on Si 1−x C x , was also measured [14]. It was found that the electron barrier height φ Bn decreased by 27 meV for every 0.4% of C.…”

Schottky-Barrier Height Tuning of Nickel Silicide on Epitaxial Silicon-Carbon Films with High Substitutional Carbon Content

“…In particular, achieving low contact resistance on Si 1-y C y with high substitutional carbon content (y or C sub ) is important for realizing high performance levels. Recently, it has been reported that the electron barrier height Φ B N of NiSi can be modulated linearly with C sub of 0.15, 0.28, 0.4% in Si 1-y C y films [3].…”