scholarly journals Comparison of ohmic contact formation of titanium and zirconium on boron doped diamond

MRS Advances ◽  
2018 ◽  
Vol 3 (33) ◽  
pp. 1931-1935
Author(s):  
V. Mortet ◽  
A. Taylor ◽  
M. Davydova ◽  
L. Fekete ◽  
Z. Vlčková Živcová ◽  
...  
Keyword(s):  
High Temperature ◽  
Contact Resistance ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Microwave Plasma ◽  
Specific Contact Resistance ◽  
High Temperature Annealing ◽  
Boron Doped Diamond ◽  
Boron Doped ◽  
Specific Contact

ABSTRACTWith a high affinity to carbon comparable to titanium and an electrically conductive carbide, zirconium has potential to form ohmic contact on boron doped diamond. In this work, formation of ohmic contacts on boron doped diamond using zirconium is studied in comparison to titanium. Boron doped diamond epitaxial layers have been grown by microwave plasma enhanced chemical vapour deposition with various B/C ratio. Circular Transmission Line Model structures were fabricated using standard micro-fabrication technologies. Specific contact resistance of fabricated contacts was determined for different boron concentrations and for various annealing temperatures. Ohmic contacts using zirconium are formed after annealing at 400 °C. Specific contact resistance steadily decreases with high temperature annealing down to a value of ca. 1 mΩ.cm2 after annealing at 700 °C for highly boron doped diamond. In comparison, titanium contact fabricated on highly doped diamond appears not stable under high temperature annealing.

Influence of Ni and Nb thickness on low specific contact resistance and high-temperature reliability of ohmic contacts to 4H-SiC

2019 ◽  
Vol 58 (11) ◽  
pp. 116501 ◽  
Author(s):  
Vuong Van Cuong ◽  
Seiji Ishikawa ◽  
Tomonori Maeda ◽  
Hiroshi Sezaki ◽  
Satoshi Yasuno ◽  
...  
Keyword(s):  
High Temperature ◽  
Contact Resistance ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Specific Contact

Dual Role of Tin Reaction Barrier in Gold-Based Metallization to GaAs

1993 ◽  
Vol 300 ◽  
Author(s):  
A. Piotrowska ◽  
E. Kaminska ◽  
M. Guziewicz ◽  
S. Kwiatkowski ◽  
A. Turos
Keyword(s):  
Magnetron Sputtering ◽  
Contact Resistance ◽  
Ohmic Contact ◽  
Diffusion Barrier ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Tin Films ◽  
Specific Contact ◽  
Tin Diffusion Barrier

ABSTRACTThe formation of ohmic contacts to p-GaAs based on Au-Zn system comprising a TiN diffusion barrier has been investigated using 2 MeV He+ RBS and the specific contact resistance measurements. It has been proved that TiN films deposited by reactive RF bias magnetron sputtering serves two purposes. First it suppresses the arsenic evaporation and thus confines the reaction between AuZn and GaAs. Second, it prevents intermixing between p-GaAs/Au(Zn) ohmic contact and an overlayer of Au.

Formation of Ni/Pt/Au Ohmic Contacts to p-GaN

1997 ◽  
Vol 482 ◽  
Author(s):  
Ja-Soon Jang ◽  
Hyo-Gun Kim ◽  
Kyung-Hyun Park ◽  
Chang-Sub Um ◽  
Il-Ki Han ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Chemical Vapor ◽  
Electron Beam Evaporation ◽  
Specific Contact Resistance ◽  
Metal Thin Films ◽  
Linear Behavior ◽  
Specific Contact ◽  
P Type

AbstractWe report a new Ni/Pt/Au (20/30/80 nm) metallization scheme to achieve a low ohmic contacts to p-type GaN with a carrier concentration of 9.4 × 1016 cm-3. A Mg-doped GaN layer (0.5 μm) was grown on (0001) sapphire substrate by metalorganic chemical vapor deposition (MOCVD). All metal thin films were deposited on the p-GaN layer in an electron-beam evaporation system. Samples were annealed by a rapid thermal annealing (RTA) process at a range of temperatures from 300 °C to 850 °C under a flowing Ar atmosphere. A circulartransmission line model (c-TLM) was employed to calculate the specific contact resistance, and current-voltage (I-V) data were measured with HP4155A. The Ni/Pt/Au contacts without the annealing process showed nearly rectifying characteristics. The ohmic contacts were formed on the samples annealed at 500 °C for 30 sec and the I-V data showed a linear behavior. The specific contact resistance was 2.1 × 10-2 Ωcm2. However with increasing the annealing temperature above 600 °C, ohmic contacts were again degraded. Auger electron spectroscopy (AES) depth profiles were used to investigate the interfacial reactions between the trilayer and GaN. AES results suggested that Pt plays a significant role in forming ohmic contact as an acceptor at the interface. Atomic force microscope (AFM) also showed that the samples with good ohmic contact have very smooth surface.

scholarly journals Circular test structures for determining the specific contact resistance of ohmic contacts

2017 ◽  
Vol 30 (3) ◽  
pp. 313-326 ◽  
Author(s):  
Anthony Holland ◽  
Yue Pan ◽  
Mohammad Alnassar ◽  
Stanley Luong
Keyword(s):  
Finite Element ◽  
Contact Resistance ◽  
Finite Element Modeling ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Wave Mechanics ◽  
Element Modeling ◽  
Specific Contact ◽  
Modeling Software

Though the transport of charge carriers across a metal-semiconductor ohmic interface is a complex process in the realm of electron wave mechanics, such an interface is practically characterised by its specific contact resistance. Error correction has been a major concern in regard to specific contact resistance test structures and investigations by finite element modeling demonstrate that test structures utilising circular contacts can be more reliable than those designed to have square shaped contacts as test contacts become necessarily smaller. Finite element modeling software NASTRAN can be used effectively for designing and modeling ohmic contact test structures and can be used to show that circular contacts are efficient in minimising error in determining specific contact resistance from such test structures. Full semiconductor modeling software is expensive and for ohmic contact investigations is not required when the approach used is to investigate test structures considering the ohmic interface as effectively resistive.

The Formation Mechanism of Ni-Based Ohmic Contacts to 4H-n-SiC

2012 ◽  
Vol 717-720 ◽  
pp. 833-836 ◽  
Author(s):  
Andrian V. Kuchuk ◽  
Krystyna Gołaszewska ◽  
Vasyl P. Kladko ◽  
M. Guziewicz ◽  
Marek Wzorek ◽  
...  
Keyword(s):  
High Temperature ◽  
Electrical Transport ◽  
Ohmic Contacts ◽  
Structural Changes ◽  
Specific Contact Resistance ◽  
Main Role ◽  
High Temperature Annealing ◽  
Electrical Transport Properties ◽  
Barrier Heights ◽  
Specific Contact

In this work the electrical properties of Ni and Ni2Si contacts on n-type 4H-SiC were correlated to the strong structural changes at the contact/SiC interface upon annealing. We can conclude that only δ-Ni2Si grains play a main role in determining electrical transport properties of the Ni-based ohmic contacts to n-SiC. It is presumed that a recrystallization and texturization of δ-Ni2Si phase on (0001)SiC-surface during high temperature annealing (> 900°C) contributes to the change of barrier heights, as well as specific contact resistance of contacts.

Formation of the Uniform Interface Ni/4H-SiC Ohmic Contact with Titanium as Barrier Layer

2018 ◽  
Vol 924 ◽  
pp. 397-400
Author(s):  
Moonkyong Na ◽  
In Ho Kang ◽  
Jeong Hyun Moon ◽  
Wook Bahng
Keyword(s):  
Contact Resistance ◽  
Barrier Layer ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Metal Structures ◽  
Uniform Interface ◽  
Specific Contact ◽  
Thermal Annealing Process ◽  
Contact Metal

Nickel (Ni) is the most widely used metal for the formation of ohmic contact on n-type SiC. However, the irregular contact can potentially cause degradation in the device performance. To form the uniform ohmic interface, titanium (Ti) was applied as a barrier layer. Ni/Ti/SiC and Ti/Ni/SiC contact metal structures were prepared, and ohmic contacts were formed using a rapid thermal annealing process. The interfacial properties of both contact metal structures were enhanced by applying the Ti layer. The specific contact resistance of ohmic contacts showed a slightly lower or similar value (~ low 105 Ωcm2) compared with the specific contact resistance values formed from only the Ni contact metal.

Ni-Al-Ti Ohmic Contacts on Al Implanted 4H-SiC

2017 ◽  
Vol 897 ◽  
pp. 391-394 ◽  
Author(s):  
P. Fedeli ◽  
Maurizio Puzzanghera ◽  
Francesco Moscatelli ◽  
Renato Amaral Minamisawa ◽  
Giovanni Alfieri ◽  
...  
Keyword(s):  
High Temperature ◽  
Contact Resistance ◽  
Ohmic Contacts ◽  
Atomic Ratio ◽  
Specific Contact Resistance ◽  
Specific Contact ◽  
P Type

This study shows that an Al-Ti bilayer with an Al to Ti atomic ratio suitable forohmic contacts on p-type 4H-SiC can be covered by a Ni film during the high temperature alloying process, without altering the ohmic nature, while eliminating a detrimental contact morphology caused by the presence of molten Al-Si during alloying. On 1×1020 cm-3 Al-implanted 4H-SiC layer, the RT specific contact resistance of this Ni-Al-Ti contact measured by TLM-C method is (3 ± 1)×10-6 Ωcm2.

Electrical Modelling and Characterisation of Alloyed Ohmic Contacts

1993 ◽  
Vol 318 ◽  
Author(s):  
Geoffrey K. Reeves ◽  
Patrick W. Leech ◽  
H. Barry Harrison
Keyword(s):  
Contact Resistance ◽  
Transmission Line ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Realistic Model ◽  
Specific Contact Resistance ◽  
Transmission Line Model ◽  
Semiconductor Interface ◽  
Line Model ◽  
Specific Contact

ABSTRACTThis paper briefly reviews the standard Transmission Line Model (TLM) commonly used to measure the specific contact resistance of a planar ohmic contact. It is proposed that in the case of a typical Au-Ge-Ni alloyed ohmic contact, a more realistic model would need to take into account the presence of the alloyed layer at the metal-semiconductor interface. An alternative is described which is based on three contact layers and the two interfaces between them, thus forming a Tri-Layer Transmission Line Model (TLTLM). Expressions are given for the contact resistance Rc and the contact end resistance Re of this structure, together with a current division factor, f. Values for the parameters of this model are inferred from experimentally reported values of Rc and Re for two types of contact.

Titanium Tungsten (TiW) for Ohmic contacts to n-and p-type 4H-SiC

2000 ◽  
Vol 640 ◽  
Author(s):  
S.-K. Lee ◽  
C.-M. Zetterling ◽  
M. Östling
Keyword(s):  
High Temperature ◽  
Contact Resistance ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Term Stability ◽  
Long Term Stability ◽  
Ohmic Behavior ◽  
Specific Contact ◽  
P Type

ABSTRACTIn the present work, we investigated sputtered titanium tungsten (TiW) contacts for Ohmic contacts to both n- and p-type 4H-SiC with long-term stability under high temperature (500°C).. Epitaxial layers with a doping concentration of 1.3×1019 and 6×1018 cm−3 were used. After high temperature annealing (>950°C) sputtered TiW contacts showed Ohmic behavior with good uniform distribution of the specific contact resistance. We obtained an average specific contact resistance (pc) of 4×10−5 Ωcm2 and 1.2 ∼ 1.7×10−4 Ωcm2 for p- and n-type, respectively from linear TLM measurement. We also found some variation of the specific contact resistance and the sheet resistance from our TLM measurement for p-type contacts. We will discuss this behavior with the measurement of SIMS. Long-term stability with a top-cap layer is also discussed

High Temperature Stable WSi2-Contacts on p-6H-Silicon Carbide

1999 ◽  
Vol 572 ◽  
Author(s):  
Frank Erler ◽  
Henry Romanus ◽  
Jörg K. N. Lindner ◽  
Lothar Spiess
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Electrical Properties ◽  
Contact Resistance ◽  
Cross Section ◽  
Ohmic Contact ◽  
Argon Atmosphere ◽  
Specific Contact Resistance ◽  
Transmission Line Model ◽  
Specific Contact

ABSTRACTAmorphous tungsten-silicon layers were deposited by DC co-sputtering and subsequently annealed in an argon atmosphere up to 1325 K to form tetragonal crystalline WSi2. Al-implanted p-6H-SiC exhibits a small depletion area forming an ohmic contact with low specific contact resistance. A modified Circular Transmission Line Model (CTLM), introduced by Marlow & Das [1] and Reeves [2], was used to characterize the electrical properties of the prepared contacts in the range between 300 K and 650 K. Deviations between calculated fieldemission contact resistances and measured contact resistances (ρc=2·10−2 Ωcm2, T=650 K) could be explained by TEM-cross section investigations. These deviations are caused by inhomogeneous contact interfaces originating from technological difficulties during contact preparation.

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