scholarly journals Current transport through ohmic contacts to indiume nitride with high defect density

2017 ◽  
Author(s):  
P. O. Sai ◽  
N. V. Safriuk ◽  
V. V. Shynkarenko
Keyword(s):  
Ohmic Contacts ◽  
Defect Density ◽  
Current Transport ◽  
High Defect Density

Current Transport in Ti/Al/Ni/Au Ohmic Contacts to GaN and AlGaN

2007 ◽  
Vol 556-557 ◽  
pp. 1027-1030 ◽  
Author(s):  
Ferdinando Iucolano ◽  
Fabrizio Roccaforte ◽  
Filippo Giannazzo ◽  
A. Alberti ◽  
Vito Raineri
Keyword(s):  
Contact Resistance ◽  
Field Emission ◽  
Ohmic Contacts ◽  
Theoretical Models ◽  
Specific Contact Resistance ◽  
Strong Increase ◽  
Current Transport ◽  
Electrical Characteristics ◽  
Structural And Electrical Properties ◽  
Specific Contact

In this work, the structural and electrical properties of Ti/Al/Ni/Au contacts on n-type Gallium Nitride were studied. An ohmic behaviour was observed after annealing above 700°C. The structural analysis showed the formation of an interfacial TiN layer and different phases in the reacted layer (AlNi, AlAu4, Al2Au) upon annealing. The temperature dependence of the specific contact resistance demonstrated that the current transport occurs through thermoionic field emission in the contacts annealed at 600°C, and field emission after annealing at higher temperatures. By fitting the data with theoretical models, a reduction of the Schottky barrier from 1.21eV after annealing at 600°C to 0.81eV at 800°C was demonstrated, together with a strong increase of the carrier concentration at the interface. The reduction of the contact resistance upon annealing was discussed by correlating the structural and electrical characteristics of the contacts.

scholarly journals Broken symmetry of in-gap quasiparticle excitations in superconducting FeSe(001) with high defect density

2018 ◽  
Vol 98 (22) ◽  
Author(s):  
Jonathan Baptista ◽  
Sergio Vlaic ◽  
Pierre Toulemonde ◽  
Sandra Karlsson ◽  
Pierre Strobel ◽  
...  
Keyword(s):  
Defect Density ◽  
Broken Symmetry ◽  
High Defect Density ◽  
Quasiparticle Excitations

The Role of Charged Defects In Current Transport Through Hydrogenated Amorphous Silicon Alloys

1998 ◽  
Vol 507 ◽  
Author(s):  
S.P. Lau ◽  
J.M. Shannon ◽  
B.J. Sealy ◽  
J.M. Marshall
Keyword(s):  
Silicon Nitride ◽  
Amorphous Silicon ◽  
Defect Density ◽  
Current Transport ◽  
Dangling Bond ◽  
Silicon Alloys ◽  
Metal Structures ◽  
Bond State ◽  
Donor States ◽  
Charged Defects

ABSTRACTCurrent transport in metal-semiconductor-metal structures based on amorphous silicon alloys has been studied in relation to the density of dangling bond state defects. The density of defects was changed by varying alloy composition or by current stressing. We show that the change of current-voltage characteristics and activation energy with defect density and the onset of Poole-Frenkel conduction with composition require charged defects. It is found that there are more charged defects in amorphous silicon nitride (a-Si1−xNx:H) than in amorphous silicon carbide (a-Si1−xCx:H). In addition, an excess of negatively charged dangling bond defects compared to positively charged dangling bond defects is observed in a-Si1−xNx:H films. This is attributed to the presence of N4+ act as the donor states in silicon nitride. We find that the density of charged dangling bond defects can be higher than 1019cm−3.

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.

Current Transport in Low-Resistance Metal-InP Contacts

1993 ◽  
Vol 300 ◽  
Author(s):  
Thomas Clausen ◽  
Otto Leistiko
Keyword(s):  
Schottky Barrier ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Current Flow ◽  
Thermionic Emission ◽  
Transport Processes ◽  
Potential Difference ◽  
Current Transport ◽  
Diffusion Limited ◽  
P Type

ABSTRACTThe limiting transport processes for current flow across metal-semiconductor (MS) ohmic contacts to n- and p-type InP have been investigated for Au-based metallizations containing the doping elements Germanium and Zinc. It has been found that the Schottky barrier is lowered and in some cases vanishes during annealing. The current flow for an optimal ohmic contact is diffusion limited by a Fermi potential difference between the alloyed metallization and the bulk InP. For non-optimal ohmic contacts the current flow is also limited by thermionic emission across a low effective Schottky barrier.

The Concentration of (SiH2)n Sites in Low and High Defect Density a-Si:H

2006 ◽  
Vol 910 ◽  
Author(s):  
David C. Bobela ◽  
T. Su ◽  
P. C. Taylor ◽  
A. Madan ◽  
G. Ganguly
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Hydrogen Content ◽  
Defect Density ◽  
Hydrogenated Amorphous Silicon ◽  
Proton Nuclear Magnetic Resonance ◽  
Dangling Bond ◽  
High Defect Density ◽  
Quality Material ◽  
Hydrogenated Amorphous

AbstractThe concentration of polysilane chains (SiH2)n, where n≥1, is estimated for higher quality hydrogenated amorphous silicon (a-Si:H) by pulsed proton nuclear magnetic resonance techniques (1H NMR). Our measurements indicate the minimum hydrogen content of approximately 10% of the total hydrogen is in the (SiH2)n configuration. Similar measurements in a high defect density sample (1017 silicon dangling bond defects cm-3) show that (SiH2)n sites account for ~ 15% of the total hydrogen. While the (SiH2)n infrared absorption (IR) modes are observed in the highly defective sample, no such modes are seen in the higher quality material. The results indicate that a significant amount of the total hydrogen content exists as (SiH2)n regardless of film quality.

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