Characteristics Of Schottky Barrier Diodes Research Articles

Nickel Silicide Formation and Related Schottky Barrier Diode Characteristics

Nickel silicide was formed by heat‐treating Ni film on single‐crystal Si or by codepositing Ni and Si. Barrier height of nickel silicide was examined in relation to phase differences identified by x‐ray diffraction analysis and x‐ray photoelectron spectroscopy. It was found that silicide phase and Si substrate orientation did not affect barrier height.

Phase interaction in GaAs contacts with group I metals and its relationship to the degradation of structures with a Schottky barrier

The methods of Rutherford back scattering of helium ions and x-ray diffraction and electron microscope analysis are used to study phase interaction in GaAs contacts with layers of group I metals (Cu, Ag, Au) with annealings in a hydrogen atmosphere. The nature of the interaction and the mechanisms of degradation of the volt-ampere characteristics of Schottky barrier diodes are discussed.

Amorphous silicon for photovoltaics produced by new microwave plasma-deposition techniques

Amorphous hydrogenated silicon (a-Si :H) has been prepared by microwave (2.45 GHz) plasmas in Ar–SiH4 mixtures using two different deposition systems, a large-volume microwave plasma (LMP) apparatus, and a Surfatron system. Films of a-Si:H are characterized structurally (primarily by scanning electron microscopy), and by Fourier transform ir spectroscopy, as well as according to their electro-optical properties (dark and photoconductivity, I-V characteristics of Schottky-barrier diodes). Although microwave plasmas are thought to differ significantly from conventional lower frequency plasmas, results of the present characterizations show no evidence of this. Deposition in the Surfatron system gives rise to device-grade a-Si:H, as demonstrated by Schottky cell efficiences exceeding 3%. We have been unable to duplicate this in the LMP system in spite of nominally identical fabrication conditions; these films have gross columnar morphology, and they react with atmospheric constituents to give a-Si:(H, C, O) alloys. More pronounced ion bombardment of the substrate during deposition is thought to account for the better quality of Surfatron films.Finally, an ageing effect of Au/a-Si:H/Sb–Cr Schottky diodes is described, unlike any reported hitherto; in a typical device, conversion efficiency was observed to rise by roughly 60% after about 2 months, then it decreased slowly. Preliminary investigations of this effect using various surface analytical techniques suggest that Au acts as a catalyst for room-temperature chemical reactions between a-Si:H and atmospheric constituents, primarily oxygen and water vapor.

Pile up of implanted phosphorus during palladium silicide formation and the characteristics of Schottky barrier diodes

Schottky barrier diodes are fabricated on silicon surfaces whose impurity concentrations are controlled by ion implantation of phosphorus. The barriers are produced from Pd2Si or Al–Si. The forward voltages of Schottky barrier diodes made from Pd2Si show a much greater lowering than those made from Al–Si for implanted doses of 5×1013 cm−2 and higher. Spreading resistance measurements show that the implanted phosphorus atoms are piled up at the Pd2Si–Si interface during Pd2Si formation. This causes reduction in the effective barrier height.

Redistribution of implanted phosphorus after platinum silicide formation and the characteristics of Schottky barrier diodes

Schottky barrier diodes are fabricated on silicon surfaces whose impurity concentrations are controlled by ion implantation techniques. The barriers are produced by PtSi or Al-Si. The forward characteristics of the diodes show that the forward voltages of Schottky barrier diodes made by PtSi are lower than those made by Al-Si for implanted doses of 2×1013 cm−2 and higher. Spreading resistance measurements show that the implanted phosphorus atoms are piled up near the PtSi-Si interface during PtSi formation. This phenomenon causes reduction of the effective barrier height.

Characteristics of Schottky Barrier Diodes in P-doped Amorphous Si: H

Schottky barrier diodes were fabricated using P-doped a-Si: H films for different doping ratio (PH3/SiH4), and their I-V and C-V characteristics have been presented systematically. The effective density of gap states (NI) deduced from a 1/C2-V curve increases with an increase in a doping level of P atoms. NI is strongly correlated with ICTS and PAS data which are more directly associated with a density of gap states.

THEORETICAL ANALYSES OF a-Si : H DIODE CHARACTERISTICS

A mathematical modelling of a-Si : H Schottky barrier diode characteristics has revealed an interesting relation between the observed quality factor and the composition of the diode current. Each component, i.e. the drift/diffusion current JD or the recombination current JR has a characteristic value of the quality factor, β 1.8 for JR. The relative magnitudes of the two components vary with the device thickness, the density of localized states, the surface barrier potential and the recombination mechanism. Thus, the observed values of quality factor can be correlated with the material parameters and indicate the upper or lower limits of the carrier recombination lifetime.

Al/Si界面状態とショットキ・バリア・ダイオード特性との関係

Al/Si界面状態とショットキ・バリア・ダイオード特性との関係

Influence of structural defects and concentration inhomogeneities in GaAs epitaxial layers on reverse I-U characteristics of schottky barrier diodes

Influence of structural defects and concentration inhomogeneities in GaAs epitaxial layers on reverse I-U characteristics of schottky barrier diodes

Effect of deep impurity levels on Schottky barrier diode characteristics

In the presence of an arbitrary number of deep donor levels volt-ampere and volt-farad characteristics are obtained for the Schottky barrier diode which contains a thin dielectric layer between the metal and the semiconductor. The analysis of these characteristics shows that the deep levels can significantly influence both the capacitance and the rectifying properties of the Schottky diode; the thicker the dielectric layer, the greater the effect of the deep levels upon volt-ampere relationship and the lesser upon volt-farad one. One can determine the parameters of the deep levels from these relationships. The results of the calculation are in agreement with the data of the experiment performed.

Effect of deep impurity levels on Schottky barrier diode characteristics : A. N. Korol, M. Ye Kitsai, V. I. Strikha and D. I. Sheka. Solid-St. Electron.18, 375 (1975)

Effect of deep impurity levels on Schottky barrier diode characteristics : A. N. Korol, M. Ye Kitsai, V. I. Strikha and D. I. Sheka. Solid-St. Electron.18, 375 (1975)

Homogeneous solution grown epitaxial GaAs by tin doping

Tin doped epitaxial GaAs single crystals were grown from a Ga solution. The C-V characteristics of Schottky barrier diodes were used to determine the electron concentration profiles of the GaAs crystals. These profiles were flat within ± 5 per cent to a depth of 165 μ. The electron concentration was controlled at specified values between 3 × 10 14 and 5 × 10 16 cm −3. The distribution coefficient of tin in GaAs is 1 × 10 −4 between 800 and 850°C.