Effect of near‐contact regions on the interpretation of ohmic behavior in trap‐dominated relaxation semiconductors

1992 ◽  
Vol 72 (6) ◽  
pp. 2294-2298 ◽  
Author(s):  
N. Derhacobian ◽  
J. H. Madok ◽  
N. M. Haegel
Keyword(s):  
Ohmic Behavior ◽  
Relaxation Semiconductors

Adjustable electrical characteristics in hybrid Si/PEDOT:PSS core/shell nanowire hetero-junctions

2017 ◽  
Vol 5 (16) ◽  
pp. 3932-3936 ◽  
Author(s):  
Wenhui Lu ◽  
Shuai Zhang ◽  
Enqi Dai ◽  
Bin Miao ◽  
Yiran Peng ◽  
...  
Keyword(s):  
Core Shell ◽  
Electrical Characteristics ◽  
Ohmic Behavior ◽  
P Type

Si/PEDOT:PSS core/shell nanowire hetero-junctions with adjustable electrical characteristics are reported. They exhibit an ohmic behavior ascribed to p-type Si/PEDOT:PSS, whereas n-type Si/PEDOT:PSS displays a rectifying nature.

Investigation of Ge, As, and Au Diffusion in Non-Alloyed Epitaxial Au-Ge Ohmic Contacts to n-GaAs Using Secondary Ion Mass Spectroscopy Backside Sputter Depth-Profiling

1991 ◽  
Vol 240 ◽  
Author(s):  
H. S. LEE ◽  
R. T. Lareau ◽  
S. N. Schauer ◽  
R. P. Moerkirk ◽  
K. A. Jones ◽  
...  
Keyword(s):  
Ohmic Contacts ◽  
Ion Beam ◽  
Depth Profiling ◽  
Depth Resolution ◽  
High Concentration ◽  
Ohmic Behavior ◽  
Preferential Sputtering ◽  
Specific Contact ◽  
Secondary Ion ◽  
Diffusion Profiles

ABSTRACTA SIMS backside sputter depth-profile technique using marker layers is employed to characterize the diffusion profiles of the Ge, As, and Au in the Au-Ge contacts after annealing at 320 C for various times. This technique overcomes difficulties such as ion beam mixing and preferential sputtering and results in high depth resolution measurements since diffusion profiles are measured from low to high concentration. Localized reactions in the form of islands were observed across the surface of the contact after annealing and were composed of Au, Ge, and As, as determined by SIMS imaging and Auger depth profiling. Backside SIMS profiles indicate both Ge and Au diffusion into the GaAs substrate in the isalnd regions. Ohmic behavior was obtained after a 3 hour anneal with a the lowest average specific contact resistivity found to be ∼ 7 × 100−6 Ω- cm2.

Effect of Au distribution in NiO/Au film on the ohmic contact formation to p-type GaN

2005 ◽  
Vol 20 (2) ◽  
pp. 456-463 ◽  
Author(s):  
Jiin-Long Yang ◽  
J.S. Chen ◽  
S.J. Chang
Keyword(s):  
Electron Microscopy ◽  
Ohmic Contact ◽  
Incident Angle ◽  
Specific Contact Resistance ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Ohmic Behavior ◽  
Transmission Electron ◽  
Specific Contact ◽  
P Type

The distribution of Au and NiO in NiO/Au ohmic contact on p-type GaN was investigated in this work. Au (5 nm) films were deposited on p-GaN substrates by magnetron sputtering. Some of the Au films were preheated in N2 ambient to agglomerate into semi-connected structure (abbreviated by agg-Au); others were not preheated and remained the continuous (abbreviated by cont-Au). A NiO film (5 nm) was deposited on both types of samples, and all samples were subsequently annealed in N2 ambient at the temperatures ranging from 100 to 500 °C. The surface morphology, phases, and cross-sectional microstructure were investigated by scanning electron microscopy, glancing incident angle x-ray diffraction, and transmission electron microscopy. I-V measurement on the contacts indicates that only the 400 °C annealed NiO/cont-Au/p-GaN sample exhibits ohmic behavior and its specific contact resistance (ρc) is 8.93 × 10−3 Ω cm2. After annealing, Au and NiO contact to GaN individually in the NiO/agg-Au/p-GaN system while the Au and NiO layers become tangled in the NiO/cont-Au/p-GaN system. As a result, the highly tangled NiO-Au structure shall be the key to achieve the ohmic behavior for NiO/cont-Au/p-GaN system.

scholarly journals Electrical behavior of graphene under temperature effect and survey of I–T curve

2019 ◽  
Vol 13 (4) ◽  
pp. 351-356
Author(s):  
M. Haditale ◽  
R. S. Dariani ◽  
E. Ghasemian Lemraski
Keyword(s):  
Temperature Effect ◽  
Effect Of Temperature ◽  
Electrical Behavior ◽  
Electrochemical Exfoliation ◽  
Ohmic Behavior ◽  
Graphene Flakes ◽  
Spray Volume

Abstract Graphene flakes were made from electrochemical exfoliation. To study graphene planes, different volumes of graphene solutions (1, 2, 4, and 7 ml) were sprayed on glass lamellae to get different graphene planes. I–V curve of all samples shows ohmic behavior with resistance in the order of kΩ which increases the slope of the I–V curve with increasing graphene planes (spray volume). The effect of temperature on all samples shows a clear jump in I–T curves. It is found that up to 150 °C current is almost constant, but after that current increases highly in the range of 1.8–10 times and resistance reduces sharply. Also, samples with lower graphene planes affected highly with temperature effect.

scholarly journals Behavior of W and WSix Contact Metallization on n- and p- Type GaN

1999 ◽  
Vol 4 (S1) ◽  
pp. 684-690
Author(s):  
X. A. Cao ◽  
F. Ren ◽  
J. R. Lothian ◽  
S. J. Pearton ◽  
C. R. Abernathy ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Annealing Temperature ◽  
Specific Contact Resistance ◽  
Ohmic Behavior ◽  
Contact Metallization ◽  
Specific Contact ◽  
Heavily Doped ◽  
Sputter Deposited ◽  
Optimum Annealing Temperature ◽  
P Type

Sputter-deposited W-based contacts on p-GaN (NA∼1018 cm−3) display non-ohmic behavior independent of annealing temperature when measured at 25°C. The transition to ohmic behavior occurs above ∼250°C as more of the acceptors become ionized. The optimum annealing temperature is ∼700°C under these conditions. These contacts are much more thermally stable than the conventional Ni/Au metallization, which shows a severely degraded morphology even at 700°C. W-based contacts may be ohmic as-deposited on very heavily doped n-GaN, and the specific contact resistance improves with annealing up to ∼900°C.

Non-ohmic behavior in a-Se80−xTe20Cdx thin films

2006 ◽  
Vol 60 (13-14) ◽  
pp. 1640-1645 ◽  
Author(s):  
S.P. Singh ◽  
A. Kumar ◽  
S. Kumar
Keyword(s):  
Thin Films ◽  
Ohmic Behavior

Current Transport Mechanisms in Au-Free Metallizations for CMOS Compatible GaN HEMT Technology

2020 ◽  
Vol 1004 ◽  
pp. 725-730
Author(s):  
Fabrizio Roccaforte ◽  
Monia Spera ◽  
Salvatore Di Franco ◽  
Raffaella Lo Nigro ◽  
Patrick Fiorenza ◽  
...  
Keyword(s):  
Barrier Height ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Current Transport ◽  
Large Area ◽  
Si Substrates ◽  
Ohmic Behavior ◽  
Specific Contact ◽  
Thermionic Field Emission

Gallium nitride (GaN) and its AlGaN/GaN heterostructures grown on large area Si substrates are promising systems to fabricate power devices inside the existing Si CMOS lines. For this purpose, however, Au-free metallizations are required to avoid cross contaminations. In this paper, the mechanisms of current transport in Au-free metallization on AlGaN/GaN heterostructures are studied, with a focus on non-recessed Ti/Al/Ti Ohmic contacts. In particular, an Ohmic behavior of Ti/Al/Ti stacks was observed after an annealing at moderate temperature (600°C). The values of the specific contact resistance ρc decreased from 1.6×104 Ω.cm2 to 7×105 Ω.cm2 with increasing the annealing time from 60 to 180s. The temperature dependence of ρc indicated that the current flow is ruled by a thermionic field emission (TFE) mechanism, with barrier height values of 0.58 eV and 0.52 eV, respectively. Finally, preliminary results on the forward and reverse bias characterization of Au-free tungsten carbide (WC) Schottky contacts are presented. This contact exhibited a barrier height value of 0.82 eV.

Ni, NiSi2 and Si Secondary Ohmic Contacts on SiC with High Thermal Stability

2013 ◽  
Vol 740-742 ◽  
pp. 797-800 ◽  
Author(s):  
Stanislav Cichoň ◽  
Petr Macháč ◽  
Jiří Vojtík
Keyword(s):  
Thermal Stability ◽  
Ohmic Contacts ◽  
High Thermal Stability ◽  
Secondary Contact ◽  
High Corrosion Resistance ◽  
Contact Materials ◽  
Adverse Conditions ◽  
Thermal Test ◽  
Ohmic Behavior ◽  
Primary Contact

A method for formation of enhanced ohmic contacts on SiC for operation under adverse conditions has been studied. Ni, NiSi2 and Si ohmic contacts were prepared and tested at 300°C on air for hundreds of hours. NiSi2 and Si showed high thermal stability. Moreover, also the so called secondary contacts showed preserved good electrical and structural properties in the thermal test. The secondary ohmic contacts are formed from original ohmic contacts after they are etched off and replaced with new ones. Secondary ohmic contacts originate in a certain surface modification of the SiC substrate created during high temperature annealing of the original contact. All applied contact materials enable formation of quality secondary contacts which is especially noteworthy at NiSi2 and Si. The results bring new SiC device design perspectives with the application of secondary ohmic contacts. For example, the contact is designed so that the primary contact makes as good ohmic behavior as possible with the secondary contact providing further important contact properties as high corrosion resistance, wire-bonding simplicity etc.

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