The Microstructure and Electrical Properties of Directly Deposited TiN Ohmic Contacts to Gallium Nitride.

1999 ◽  
Vol 595 ◽  
Author(s):  
P. Ruterana ◽  
G. Nouet ◽  
Th. Kehagias ◽  
Ph. Komninou ◽  
Th. Karakostas ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Electrical Properties ◽  
Film Thickness ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Epitaxial Relationship ◽  
Si Doped ◽  
P Type ◽  
20 Nm

AbstractWhen the stoichiometric TiN was deposited directly on GaN, we obtained columnar TiN grains of 5-20 nm section which cross the whole film thickness and are rotated mostly around the [111] axis. The conventional epitaxial relationship is obtained and no amorphous patches are observed at the interface. The deposition of TiN on Si doped GaN layers lead to the formation of an ohmic contact, whereas we obtain a rectifying contact on p type layers.

scholarly journals The microstructure and electrical properties of directly deposited TiN ohmic contacts to Gallium Nitride.

2000 ◽  
Vol 5 (S1) ◽  
pp. 887-893
Author(s):  
P. Ruterana ◽  
G. Nouet ◽  
Th. Kehagias ◽  
Ph. Komninou ◽  
Th. Karakostas ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Electrical Properties ◽  
Film Thickness ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Epitaxial Relationship ◽  
Si Doped ◽  
P Type ◽  
20 Nm

When the stoichiometric TiN was deposited directly on GaN, we obtained columnar TiN grains of 5-20 nm section which cross the whole film thickness and are rotated mostly around the [111] axis. The conventional epitaxial relationship is obtained and no amorphous patches are observed at the interface. The deposition of TiN on Si doped GaN layers lead to the formation of an ohmic contact, whereas we obtain a rectifying contact on p type layers.

Evolution of the Electrical and Structural Properties of Ti/Al/W Contacts to p-Type Implanted 4H-SiC upon Thermal Annealing

2015 ◽  
Vol 821-823 ◽  
pp. 428-431
Author(s):  
Marilena Vivona ◽  
Giuseppe Greco ◽  
Raffaella Lo Nigro ◽  
Salvatore di Franco ◽  
Filippo Giannazzo ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Melting Temperature ◽  
Thermal Annealing ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Good Choice ◽  
Specific Nature ◽  
Ohmic Behavior ◽  
Layer Contact ◽  
P Type

The mechanism of Ohmic contacts formation to p-type SiC is a fundamental and technological concern continuously under debate. Typically, Ti/Al-based contacts are a good choice for Ohmic contacts to p-type SiC, even though some aspects strictly related to the specific nature of Al (susceptibility to oxidation, low melting temperature, etc.) remain to be optimized. In this work, the evolution of the electrical properties of a Ti/Al/W multiple-layer contact has been studied by TLM characterization and correlated to the changes in the morphology and microstructure upon thermal annealing. The formation of an Ohmic contact has been observed after a thermal annealing at 1100°C, discussing the possible reasons determining the transition to an Ohmic behavior.

scholarly journals Thermally Stable Ohmic Contact to p-Type 4H-SiC Based on Ti3SiC2 Phase

2016 ◽  
Vol 858 ◽  
pp. 553-556 ◽  
Author(s):  
Tony Abi-Tannous ◽  
Maher Soueidan ◽  
Gabriel Ferro ◽  
Mihai Lazar ◽  
Christophe Raynaud ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Magnetron Sputtering ◽  
Ohmic Contact ◽  
Room Temperature ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Specific Contact ◽  
Thermionic Field Emission ◽  
P Type

In this study, the electrical properties of Ti3SiC2 based ohmic contacts formed on p-type 4H-SiC(0001) 4°-off substrates were studied. The Ti3SiC2 thin films were grown by thermal annealing (from 900°C to 1200°C) of Ti50Al50 layer deposited by magnetron sputtering. XRD analyzes were performed on the samples to further investigate the compounds formed after annealing. Using TLM structures, the Specific Contact Resistance (SCR) at room temperature of all contacts was measured. The temperature dependence (up to 600°C) of the SCR was studied to understand the current mechanisms at the interface and to determine the barrier height value by fitting the experimental results using the thermionic field emission theory. Aging tests showed that Ti3SiC2 based contacts were stable up to 200h at 600°C under Ar.

Correlation between the electrical properties and the interfacial microstructures of TiAl-based ohmic contacts to p-type 4H-SiC

2004 ◽  
Vol 33 (5) ◽  
pp. 460-466 ◽  
Author(s):  
S. Tsukimoto ◽  
K. Nitta ◽  
T. Sakai ◽  
M. Moriyama ◽  
Masanori Murakami
Keyword(s):  
Electrical Properties ◽  
Ohmic Contacts ◽  
P Type

Comparison between Ni-SALICIDE and Self-Aligned Lift-Off Used in Fabrication of Ohmic Contacts for SiC Power MOSFET

2019 ◽  
Vol 963 ◽  
pp. 490-493
Author(s):  
Tomasz Sledziewski ◽  
Tobias Erlbacher ◽  
Anton Bauer ◽  
Lothar Frey ◽  
Xi Ming Chen ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Silicon Dioxide ◽  
Ohmic Contacts ◽  
Positive Impact ◽  
Specific Resistance ◽  
Power Mosfet ◽  
Interlayer Dielectric ◽  
Lift Off ◽  
P Type

A comparison between self-aligned process (using lift-off) and Ni-SALICIDE used in fabrication of ohmic contacts for SiC Power MOSFET is done. Both processes are demonstrated for 3.3 kV SiC VDMOS transistors fabricated on 100 mm substrates. It is shown that the Ni-SALICIDE process with first silicidation at 500 °C does not degrade the electrical properties of silicon dioxide; particularly, a degradation of the interlayer dielectric between source and gate is not evident. Additionally, this first silicidation is found to have a positive impact on the specific resistance of contacts formed on p-type SiC using NiAl2.6% as an ohmic metal.

An Approach to Improving the Morphology and Reliability of n-SiC Ohmic Contacts to SiC Using Second-Metal Contacts

2006 ◽  
Vol 527-529 ◽  
pp. 859-862 ◽  
Author(s):  
Matthew H. Ervin ◽  
Kenneth A. Jones ◽  
Un Chul Lee ◽  
Taniya Das ◽  
M.C. Wood
Keyword(s):  
Electrical Properties ◽  
Contact Resistance ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Chemical Properties ◽  
Physical Contact ◽  
Metal Contacts ◽  
Critical Feature ◽  
Excess Carbon ◽  
Ohmic Contact Formation

While nickel ohmic contacts to n-type silicon carbide have good electrical properties, the physical contact, and therefore the reliability, can be poor. An approach is described for using the good electrical properties of Ni ohmic contacts while using another metal for its desired mechanical, thermal and/or chemical properties. In the present work, once the Ni contacts have been annealed forming nickel silicides and achieving low contact resistance, they are etched off. Removing the primary Ni contacts also eliminates the poor morphology, voids, and at least some of the excess carbon produced by the Ni/SiC reaction. The Ni contacts are then replaced by a second contact metal. This second metal displays low contact resistance as-deposited, indicating that the critical feature responsible for the ohmic contact has not been removed by the primary contact etch. Not only does this approach provide more flexibility for optimizing the contact for a given application, it also provides some insight into the ohmic contact formation mechanism.

scholarly journals Electrical Properties of Cubic InN And GaN Epitaxial Layers as a Function of Temperature

2000 ◽  
Vol 5 (S1) ◽  
pp. 216-222
Author(s):  
J.R.L. Fernandez ◽  
V.A. Chitta ◽  
E. Abramof ◽  
A. Ferreira da Silva ◽  
J.R. Leite ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electrical Properties ◽  
Carrier Concentration ◽  
Doping Level ◽  
Type Conductivity ◽  
Si Doping ◽  
Donor And Acceptor ◽  
Cubic Gan ◽  
Si Doped ◽  
P Type

Carrier concentration and mobility were measured for intrinsic cubic InN and GaN, and for Si-doped cubic GaN as a function of temperature. Metallic n-type conductivity was found for the InN, while background p-type conductivity was observed for the intrinsic GaN layer. Doping the cubic GaN with Si two regimes were observed. For low Si-doping concentrations, the samples remain p-type. Increasing the Si-doping level, the background acceptors are compensated and the samples became highly degenerated n-type. From the carrier concentration dependence on temperature, the activation energy of the donor and acceptor levels was determined. Attempts were made to determine the scattering mechanisms responsible for the behavior of the mobility as a function of temperature.

Effects of Different Post-Implantation Annealing Conditions on the Electrical Properties of Interfaces to p-Type Implanted 4H-SiC

2012 ◽  
Vol 717-720 ◽  
pp. 825-828
Author(s):  
Alessia Frazzetto ◽  
Fabrizio Roccaforte ◽  
Filippo Giannazzo ◽  
R. Lo Nigro ◽  
M. Saggio ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Electrical Parameters ◽  
Capping Layer ◽  
Annealing Conditions ◽  
Specific Contact ◽  
Activation Annealing ◽  
P Type ◽  
Post Implantation

This paper reports on the effects of different post-implantation annealings on the electrical properties of interfaces to p-type implanted 4H-SiC. The morphology of p-type implanted 4H-SiC was controlled using a capping layer during post-implantation activation annealing of the dopant. Indeed, the surface roughness of Al-implanted regions strongly depends on the use of the protective capping layer during the annealing. However, while the different morphological conditions do not affect the macroscopical electrical properties of the implanted SiC (such as the sheet resistance), they led to an improvement of the morphology and of the specific contact resistance of Ti/Al Ohmic contacts formed on the implanted regions. These electrical and morphologic improvements were associated with a lowering of Schottky barrier height. Preliminary results showed that the different activation annealing conditions of p-type implanted SiC can affect also the electrical parameters (like threshold voltage and mobility) of lateral MOSFETs.

scholarly journals Comparison of Electrical Properties of Ohmic Contact Realized on p-Type 4H-SiC

2008 ◽  
Vol 600-603 ◽  
pp. 639-642
Author(s):  
Duy Minh Nguyen ◽  
Christophe Raynaud ◽  
Mihai Lazar ◽  
Heu Vang ◽  
Dominique Planson
Keyword(s):  
Surface Roughness ◽  
Electrical Properties ◽  
Contact Resistance ◽  
Carrier Mobility ◽  
Ohmic Contacts ◽  
Series Resistance ◽  
Specific Contact Resistance ◽  
Specific Contact ◽  
P Type ◽  
Post Implantation

N+ 4H-SiC commercial substrates with n-type epilayers have been used to realize bipolar diodes and TLM structures. The p-type emitter of diodes was realized by Al implantations followed by a post-implantation annealing with or without a graphite capping layer. Ohmic contacts were formed by depositing Ti/Ni on the backside and Ni/Al on the topside of the wafer. It appears that capping the sample during the annealing reduces considerably the surface roughness and the specific contact resistance. Sheet resistance and specific contact resistance as low as 2kΩ/□ and respectively 1.75×10-4 Ωcm² at 300 K have been obtained. I-V measurements as a function of temperature have been performed from ~100 to ~500 K. The variations of the series resistance vs. temperature can be explained by the freeze-out of carriers and by the variation of carrier mobility.

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.

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