NiSi Schottky Research Articles

In situ study of the growth properties of Ni-rare earth silicides for interlayer and alloy systems on Si(100)

We report on the solid-phase reaction of thin Ni-rare earth films on a Si(100) substrate, for a variety of rare earth (RE) elements (Y, Gd, Dy, and Er). Both interlayer (Ni/RE/〈Si〉) and alloy (Ni-RE/〈Si〉) configurations were studied. The phase sequence during reaction was revealed using real-time x-ray diffraction whereas the elemental diffusion and growth kinetics were examined by real-time Rutherford backscattering spectrometry. All RE elements studied exert a similar influence on the solid phase reaction. Independent of the RE element or its initial distribution a ternary Ni2Si2RE phase forms, which ends up at the surface after NiSi growth. With respect to growth kinetics, the RE metal addition hampers the Ni diffusion process even for low concentrations of 2.5 at. %, resulting in the simultaneous growth of Ni-rich silicide and NiSi. Moreover, the formation of Ni2Si2RE during NiSi growth alters the Ni diffusion mechanism in the interlayer causing a sudden acceleration of the Ni silicide growth. Besides a significant effect on the silicide growth, we have found that adding 5 at. % Er (relative to Ni) lowers the NiSi Schottky barrier height on n-type Si(100) by approximately 0.1 eV for the interlayer and alloy configuration.

Gate-First Metal-Gate/High-$k$ n-MOSFETs With Deep Sub-nm Equivalent Oxide Thickness (0.58 nm) Fabricated With Sulfur-Implanted Schottky Source/Drain Using a Low-Temperature Process

Gate-first high- <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> /metal-gate n-MOSFETs with a deep subnanometer (sub-nm) equivalent oxide thickness (EOT) of 0.58 nm were successfully fabricated with Schottky source/drain contacts using a low-temperature process. The key to achieving such a thin EOT is the use of a low-temperature process for the NiSi Schottky source/drain formation. A sulfur implantation technique was used to overcome the Schottky barrier height between Si and NiSi, which is the main problem in NiSi Schottky source/drain fabrication. The advantage of Schottky source/drain MOSFETs over conventional source/drain MOSFETs was successfully demonstrated.

Evaluation of Lateral Ni Diffusion in Si Nanowire Schottky Contact

Lateral Ni diffusion in Si Nanowire to form NiSi schottky contact was characterized by scanning electron microscope at temperatures range from 400 to 700°. Higher temperature annealing results in longer NiSi formation and the length of NiSi increases with the annealing time. The activation energy for NiSi formation on SiNWs are found to be 0.9 eV which is lower than bulk case. One-dimensional diffusion of Ni with SiNW might be the reason for lowering the activation energy.

Analysis of thermionic emission from electrodeposited Ni–Si Schottky barriers

Ni–Si Schottky barriers are fabricated by electrodeposition using n on n + Si substrates. I – V , C – V and low temperature I – V measurements are presented. A high-quality Schottky barrier with extremely low reverse leakage current is revealed. The results are shown to fit an inhomogeneous barrier model for thermionic emission over a Schottky barrier proposed by Werner and Guttler [J.H. Werner, H.H. Guttler, Barrier inhomogeneities at Schottky contacts, J. Appl. Phys. 69 (3) (1991) 1522–1533]. A mean value of 0.76 V and a standard deviation of 66 mV is obtained for the Schottky barrier height at room temperature with a linear bias dependence. X-ray diffraction and scanning electron microscopy measurements reveal a polycrystalline Ni film with grains that span from the Ni–Si interface to the top of the Ni layer. The variation in Ni orientation is suggested as a possible source of the spatial distribution of the Schottky barrier height.

Electrodeposition of Ni-Si Schottky barriers

Electrodeposition is being used to fabricate magnetic microstructures directly on patterned n-type Si wafers of various substrate resistivities. The Ni-Si Schottky barrier is characterized and found to be of high quality for relatively low Si resistivities (1-2 /spl Omega//spl middot/cm), with extremely low reverse leakage. It is shown that a direct correlation exists among the electrodeposition potential, the roughness, and the coercivity of the films. A conductive seed layer or a back contact is not compulsory for electrodeposition on Si with resistivities up to 15 /spl Omega//spl middot/cm. This shows that electrodeposition of magnetic materials on Si might be a viable fabrication technique for magnetoresistance and spintronics applications.

Electrical characterization of NiSi/Si interfaces formed by a single and a two-step rapid thermal silicidation

This paper investigates the electrical characteristics of NiSi Schottky barrier diodes (SBD). A single-step rapid thermal process (RTP) and a two-step RTP were employed to form the SBDs. The diode structures were designed so as to minimize edge leakage. The two-step silicidation process resulted in a significant reduction of the reverse leakage current density, suggesting an improvement of the interface characteristics. Temperature-dependent current–voltage measurements were used to analyse the interface characteristics. The two-step RTP process reduces the density of non-ideal micro-contacts with low barrier height, which are responsible for the reverse leakage current.

Ni and Ni silicide Schottky contacts on n-GaN

The electrical characteristics of Ni and NiSi Schottky diodes on n-GaN have been investigated as a function of annealing. Ni diodes were found to be stable up to 500 °C for 1 h in sequential annealing, with a barrier height φ (I–V) of 0.8–0.9 eV and an n factor of ∼1.1. The barrier height deduced from C–V measurements, φ (C–V), was typically 0.15 eV higher than φ (I–V). At 600 °C the diodes failed, and Ga was found to migrate into the Ni layer. NiSi diodes were stable up to 600 °C for 1 h, φ (I–V) was found to be about 0.8–1 eV with an n-factor of about 1.15. The value of φ (C–V) was between 0.3 to 0.6 eV higher than φ (I–V), consistent with the notion of the presence of a thin insulating layer at the NiSi/GaN interface. The electrical characteristics obtained in this study are also compared with those obtained for Pt and PtSi Schottky diodes on n-GaN.

Effect of vacuum annealing on electrical characteristics of Ni-Si schottky diodes

physica status solidi (a)Volume 86, Issue 1 p. K73-K78 Short Note Effect of vacuum annealing on electrical characteristics of Ni-Si schottky diodes Tran Chot, Tran Chot Institute of Physics, Centre for Scientific Researchs of Vietnam, Hanoi Search for more papers by this author Tran Chot, Tran Chot Institute of Physics, Centre for Scientific Researchs of Vietnam, Hanoi Search for more papers by this author First published: 16 November 1984 https://doi.org/10.1002/pssa.2210860169Citations: 1 Nghia Do, Tu Liem, Hanoi, Vietnam. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume86, Issue116 November 1984Pages K73-K78 RelatedInformation

Titanium nitride as a diffusion barrier between nickel silicide and aluminum

The diffusion barrier properties of titanium nitride between nickel silicide and aluminum have been investigated in NiSi Schottky contacts on silicon for annealing temperatures of 400–600°C. No interaction between the metals of the contact structure was detected by backscattering spectrometry, even at 600°C. The electron barrier height of Schottky diodes stays constant at ϕBn = 0.67 ± 0.01 upon thermal annealing in vacuum at 500°C for 2 h . The ideality factor is n = 1.01. After 4 h, ϕ Bn decreases by about 10 mV and n rises to 1.0 6. The diodes degrade after annealing at 550°C or 600°C for 30 min.

Formation of NiSi and current transport across the NiSi-Si interface

The metallic compound NiSi has been produced by solid-solid metallurgical reaction in both n- and p-type silicon by sputtering Ni onto freshly back-sputtered silicon wafers and sintering for 5 min at 550°C. Identification of the orthorhombic (B31) monosilicide phase was made by X-ray diffraction, utilizing a glancing-angle Debye-Scherrer photograph of the 1300 Å thin-film phase on the silicon substrate. NiSi Schottky barrier diodes, formed by this technique through holes in a silica mask and containing diffused guard rings around the periphery of the metallization, yield nearly ideal reverse I– V characteristics. The data have been fitted to a thermionic emission model for current transport, with barrier heights of 0.66 and 0.45 (eV) to n- and p-type silicon, respectively. The nature of the current transport characteristics strongly indicates the presence of a dipolar charge layer at the metal-semiconductor interface caused by quantum mechanical penetration of metallic electrons into the forbidden gap of the semiconductor.