High temperature annealing behaviour of Schottky barriers on GaAs with gold and gold-gallium contacts

Wang

Crystal Growth & Design

et al. 2018

Because of the inevitable Fermi level pinning on surface/interface states of nanowires, achieving high-performance nanowire devices with controllable nanoscale contacts is always challenging but important. Herein, single-crystalline heterostructured Ga/GaAs nanowires with sharp hetero-Schottky interfaces have been successfully synthesized on amorphous substrates by utilizing Au nanoparticles as catalytic seeds via chemical vapor deposition. These nanowires are found to grow with the hemispherical Au7Ga2 catalytic tips following the vapor–liquid–solid mechanism. During the growth, simply by manipulating the source and growth temperatures, the Ga precipitation rate from Au–Ga alloy tips as well as the reaction rate of Ga precipitates with As can be reliably controlled in order to tailor the length (0–170 nm) of Ga nanowire segments obtained in the heterostructure. When configured into field-effect transistors, these Ga/GaAs NWs exhibit the p-type conductivity with a sharp hetero-Schottky barrier of ∼1.0 eV at the atomically connected Ga segment/GaAs NW body interface, in which this barrier height is close to the theoretical difference between the GaAs Fermi level (5.1–5.3 eV) and the Ga work function (∼4.3 eV), suggesting the effective formation of nanoscale contact by minimizing the Fermi level pinning, being advantageous for advanced nanoelectronics.

Section: Resultssupporting

confidence: 83%

Controlled Growth of Heterostructured Ga/GaAs Nanowires with Sharp Schottky Barrier

Wang

Crystal Growth & Design

et al. 2018

“…4a. Such Ga diffusion is consistent with the results of the Au-GaAs contact system [6]. The black spots increased as the alloying temperature increased, which indicated that Ga out-diffusion was dependent on the alloying temperature.…”

Section: Fabrication Of N-lnogaosb/p-io~ Alosh/p-gash and N-supporting

confidence: 89%

Molecular beam epitaxy of In0.23Ga0.77Sb Grown on GaAs and GaSb substrates and the fabrication of planar In0.23Ga0.77Sb transferred electron devices

Kodama¹

1993

Phys. Stat. Sol. (a)

MBF In0.23Ga0.73Sb films are grown on semi‐insulating Cr‐doped GaAs and undoped GaSb substrates, and the first planar MBE‐In0.23Ga0.77Sb transferred electron devices are fabricated and then evaluated. In the epitaxial growth process, an epitaxial layer structure such as the selection of a substrate and insertion of a high‐resistivity buffer layer of Al0.9In0.1Sb is a significant factor influencing the electrical properties of the In0.23Ga0.77Sb active layer and then determine the threshold electric field of In0.23Ga0.77Sb/Al0.9In0.1Sb/GaSb epitaxial layer structure by the application of a high‐resistivity buffer layer between the In0.23Ga0.77Sb film and the GaSb substrate. In the transferred electron device fabrication process, the contact properties of alloyed AuSn metallization to n‐In0.23Ga0.77Sb film are also investigated and evaluated.

J Mater Sci: Mater Electron

“…The exact alloying mechanism that causes the degradation of the SDs was not very clear. This will result in significant field emissions along the barrier and increase the flow through it [48]. This behavior also observed in studies on AlGaN or GaN substrates [29].…”

Section: Figurementioning

confidence: 55%

“…The expected barrier height values could not be observed due to alloying behavior. This behavior causes the AuGa compounds to change the interface chemistry of the Au-GaAs interface as a result of some Ga out-diffusion and solid-state reactions with Au, and the remaining As atoms make the semiconductor highly doped [35,37,48]. The exact alloying mechanism that causes the degradation of the SDs was not very clear.…”

Section: Figurementioning

confidence: 99%

Au–Ag binary alloys on n-GaAs substrates and effect of work functions on Schottky barrier height

Akkaya

2021

In this study, I investigated the effect of work function (ϕm) of AuxAg1-x (x=0, 0.22, 0.37, 0.71 and 1) on the Au-Ag/n-GaAs Schottky diode (SD) parameters. Ag, Au and three alloys with different compositions deposited on n-GaAs substrates by thermal evaporation method. Surface morphologies of the samples were investigated by atomic force microscope (AFM). Elementel compositions of Schottky metals were conducted by the energy dispersive X-ray spectroscop (EDX). Current-voltage (I-V) and capacitance-voltage (C-V) measurements performed at room temperature.SD parameters such as barrier height (Φb0), ideality factor (n), series resistance (Rs), and interface state density (Dit) of the SD's were calculated from the obtained I-V and C-V data. Experimental results showed that all calculated SD parameters depends on alloy composition. Lowest mean barrier height value was found as 0.789±0.022 eV for Au/n-GaAs SDs and the highest value was determined 0.847±0.008 eV for Au0.71Ag0.29/n-GaAs SDs from I-V measurements. Weak dependencies of barrier height to ϕm was exist and gap state parameter (S) determined as 0.0526. S value was close to the Bardeen limit (S=0), and indicates that Fermi level was strongly pinned in Au-Ag/n-GaAs SDs. Also, main SD parameters like series resistance (Rs), ideality factor (n), reverse bias barrier height (Φb RB ), doping density (Nd) and density of interface states (Dit) were calculated via using different methods from I-V and C-V measurement results. In addition, to determine the leakage current mechanism Poole-Frenkel emission (PFE) and Schottky emission (SE) models applied on reverse bias I-V data.