Fabrication and Characterization of Ohmic Contacts to 3C-SiC Layers Grown on Silicon

2019 ◽  
Vol 963 ◽  
pp. 485-489
Author(s):  
Monia Spera ◽  
Giuseppe Greco ◽  
Raffaella Lo Nigro ◽  
Salvatore di Franco ◽  
Domenico Corso ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
X Ray ◽  
Specific Contact ◽  
Fabrication And Characterization ◽  
P Type

This paper reports on the formation and characterization of Ohmic contacts to n-type and p-type type 3C-SiC layers grown on silicon substrates. In particular, Ohmic contact behavior was obtained either using Ni or Ti/Al/Ni layers annealed at 950°C. The values of the specific contact resistance ρc estimated by means of circular TLM (C-TLM) structures varied in the range ~ 10-3-10-5 Ωcm2, depending on the doping level of the 3C-SiC layer. A structural analysis performed by X-Ray Diffraction (XRD) allowed to identify the main phases formed upon annealing, i.e., Ni2Si and Al3Ni2. The morphology of the reacted contacts depended on that of the underlying substrate. The results can be useful for the development of a variety of devices on the cubic 3C-SiC polytype.

The Reliability of Multilevel Metallization on InGaAs/GaAs Layers

1994 ◽  
Vol 337 ◽  
Author(s):  
Edward Y. Chang ◽  
J.S. Chen ◽  
J.W. Wu ◽  
K.C. Lin
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Molecular Beam ◽  
Specific Contact Resistance ◽  
Transmission Line Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Specific Contact ◽  
Secondary Ion ◽  
Contact Metal

ABSTRACTNon-alloyed ohmic contacts using Ti/Pt/Au and Ni/Ge/Au on InGaAs/GaAs layers grown by Molecular Beam Epitaxy (MBE) have been investigated. The n-type InGaAs film has a doping concentration higher than 1X1019 cm-3. Specific contact resistance below 2X10-7 Ωcm2 could be easily achieved with Ti/Pt/Au. Due to the layer intermixing and outdiffusion of In and Ga, the specific contact resistance and sheet resistance increase after thermal treatment. When Ni/Ge/Au is used as the contact metal, the outdiffusion of In and Ga atoms is more severe than that of Ti/Pt/Au. After annealing at 450°C for two minutes, the Au4In formed and the characteristics of the contact became worse. All the phenomena illustrated above have been observed and investigated by Transmission Line Model, X-ray diffraction, Auger Electron Spectroscopy and Secondary Ion Mass Spectrum. As far as the thermal stability is concerned, it is convinced that Ti/Pt/Au is the best one of these two non-alloyed ohmic contact studied.

Fabrication and Characterization of Thermoelectric Oxide La1−xSrxCoO3 (x∼0.05) Nanofibers

2009 ◽  
Author(s):  
Weihe Xu ◽  
Shiyou Xu ◽  
Dante Smiriglio ◽  
Yong Shi
Keyword(s):  
Aluminum Foil ◽  
Complex Oxide ◽  
Electrospinning Process ◽  
X Ray Diffraction ◽  
Thermoelectric Oxide ◽  
X Ray ◽  
Fabrication And Characterization ◽  
Oxide Thermoelectric Materials ◽  
P Type

The P-type perovskite oxides La1−xSrxCoO3 (x∼0.05) are a promising group of complex oxide thermoelectric materials. The thermal electric properties of these complexes are expected to increase significantly when their dimension was reduced to nano scale. In this project, the La1-xSrxCoO3 (x∼0.05) nanofibers, with diameters in the range of ∼30–80 nm, were prepared by the electrospinning process. Various substrates such as aluminum foil, silicon dioxide, and a specially designed tester were used to collect and anneal the nanofibers. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were conducted to characterize these thermoelectric nanofibers. Finally, a thermoelectric property tester device was developed and used to measure the voltage output of the nanofibers due to the Seebeck effect. The detected signal was at the mV level and the Seebeck coefficient was positive.

Effect of Annealing on the Characteristics of Ti/Al Ohmic Contacts to p-Type 4H-SiC

2017 ◽  
Vol 897 ◽  
pp. 395-398 ◽  
Author(s):  
Yi Dan Tang ◽  
Hua Jun Shen ◽  
Xu Fang Zhang ◽  
Fei Guo ◽  
Yun Bai ◽  
...  
Keyword(s):  
Ohmic Contacts ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Effective Barrier ◽  
Current Voltage ◽  
Key Factor ◽  
Specific Contact ◽  
Different Temperatures ◽  
P Type

Ti/Al contacts deposited on p-type epilayer doped with Al at 2×1019 cm-3 are reported. The current-voltage curves of Ti/Al contacts annealed at different temperatures from 800 to 1000 °C were measured, which provided the specific contact resistances (SCRs) of 6.59×10-5 Ω/cm2 and 7.81×10-5Ω/cm2 after annealing at 900°C for 5min and 950°C for 2min, respectively. The microstructures of Ti/Al contact on P-type 4H–SiC were investigated by X-ray diffraction (XRD). The results of XRD show that the phases of Ti3SiC2 was formed at the metal/SiC interface after annealing, which could be effective to ohmic contacts on P-type 4H-SiC. The quantitative phase analysis were also discussed, which show that the phase composition of Ti3SiC2is key factor for low resistance to P-type 4H–SiC. Moreover, simulations proved that the gradual Ti3SiC2ISL reduces or eliminates the effective barrier height at the metal/Ti3SiC2/p-type and may also contribute to low contact resistivity.

Cobalt Silicide OHMIC Contacts to 6H-SiC

1994 ◽  
Vol 339 ◽  
Author(s):  
Nils Lundberg ◽  
M. Östling
Keyword(s):  
Current Density ◽  
Ohmic Contacts ◽  
Elevated Temperatures ◽  
Rutherford Backscattering Spectrometry ◽  
Temperature Stability ◽  
Specific Contact Resistance ◽  
X Ray Diffraction ◽  
Materials Analysis ◽  
X Ray ◽  
Specific Contact

ABSTRACTMaterials and electrical evaluation were performed to determine the characteristics of ohmic contacts to 6H-SiC. Both elemental metal (Co) and suicides (CoSi and CoSi2) were studied following heat treatments at 500 °C and 900 °C for 5 hours and 2 hours, respectively. Materials analysis by Rutherford Backscattering Spectrometry (RBS) and X-ray Diffraction (XRD) monitored the temperature stability of the contacts after the annealings. Current density-voltage measurements at elevated temperatures established the specific contact resistance pc.

Improvement of the Specific Contact Resistance on P-Type 4H-SiC by Using a Highly P-Typed Doped 4H-SiC Layer Selectively Grown by VLS Transport

2014 ◽  
Vol 806 ◽  
pp. 57-60
Author(s):  
Nicolas Thierry-Jebali ◽  
Arthur Vo-Ha ◽  
Davy Carole ◽  
Mihai Lazar ◽  
Gabriel Ferro ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Schottky Barrier Height ◽  
Annealing Temperature ◽  
Process Condition ◽  
Specific Contact Resistance ◽  
High Doping Level ◽  
Annealing Temperatures ◽  
Specific Contact ◽  
P Type

This work reports on the improvement of ohmic contacts made on heavily p-type doped 4H-SiC epitaxial layer selectively grown by Vapor-Liquid-Solid (VLS) transport. Even before any annealing process, the contact is ohmic. This behavior can be explained by the high doping level of the VLS layer (Al concentration > 1020 cm-3) as characterized by SIMS profiling. Upon variation of annealing temperatures, a minimum value of the Specific Contact Resistance (SCR) down to 1.3x10-6 Ω.cm2 has been obtained for both 500 °C and 800 °C annealing temperature. However, a large variation of the SCR was observed for a same process condition. This variation is mainly attributed to a variation of the Schottky Barrier Height.

AlxGa1-xN-Based Materials and Heterostructures

1996 ◽  
Vol 449 ◽  
Author(s):  
P. Kung ◽  
A. Saxler ◽  
D. Walker ◽  
X. Zhang ◽  
R. Lavado ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Bragg Reflectors ◽  
X Ray Diffraction ◽  
Chemical Vapor Deposition Growth ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Dimensional Electron Gas ◽  
P Type

ABSTRACTWe present the metalorganic chemical vapor deposition growth, n-type and p-type doping and characterization of AlxGa1-xN alloys on sapphire substrates. We report the fabrication of Bragg reflectors and the demonstration of two dimensional electron gas structures using AlxGa1-xN high quality films. We report the structural characterization of the AlxGa1-xN / GaN multilayer structures and superlattices through X-ray diffraction and transmission electron microscopy. A density of screw and mixed threading dislocations as low as 107 cm-2 was estimated in AlxGa1-xN / GaN structures. The realization of AlxGa1-xN based UV photodetectors with tailored cut-off wavelengths from 365 to 200 nm are presented.

scholarly journals Fabrication and Characterization of Al/NiO Energetic Nanomultilayers

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
YiChao Yan ◽  
Wei Shi ◽  
HongChuan Jiang ◽  
Jie Xiong ◽  
WanLi Zhang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Total Thickness ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Metallic Oxide ◽  
Promising Candidate ◽  
X Ray ◽  
Thermal Boundary Conductance ◽  
Fabrication And Characterization

The redox reaction between Al and metallic oxide has its advantage compared with intermetallic reaction and Al/NiO nanomutlilayers are a promising candidate for enhancing the performance of energetic igniter. Al/NiO nanomutlilayers with different modulation periods are prepared on alumina substrate by direct current (DC) magnetron sputtering. The thicknesses of each period are 250 nm, 500 nm, 750 nm, 1000 nm, and 1500 nm, respectively, and the total thickness is 3 μm. The X-ray diffraction (XRD) and scanning electron microscope (SEM) results of the as-deposited Al/NiO nanomutlilayers show that the NiO films are amorphous and the layered structures are clearly distinguished. The X-ray photoelectron spectroscopy (XPS) demonstrates that the thickness of Al2O3increases on the side of Al monolayer after annealing at 450°C. The thermal diffusion time becomes greater significantly as the amount of thermal boundary conductance across the interfaces increases with relatively smaller modulation period. Differential scanning calorimeter (DSC) curve suggests that the energy release per unit mass is below the theoretical heat of the reaction due to the nonstoichiometric ratio between Al and NiO and the presence of impurities.

Ohmic Contacts to p-Type InGaAs/InP with a Graded Bandgap Heterobarrier

1993 ◽  
Vol 318 ◽  
Author(s):  
Patrick W. Leech ◽  
Geoffrey K. Reeves
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Rutherford Backscattering Spectrometry ◽  
Specific Contact Resistance ◽  
Superlattice Structure ◽  
Specific Contact ◽  
P Type ◽  
Metal Layers ◽  
Anneal Temperature ◽  
Graded Bandgap

ABSTRACTOhmic contacts to p-type InP with an In0.47Ga0.53As buffer layer and an interposed superlattice of 50 Å In0.47Ga0.53As/ 50 Å InP have been investigated. Initial studies of contacts to In0.47Ga0.53As/ InP without the superlattice structure have shown that Pd/Zn/Pd/Au metallization produced a lower specific contact resistance (pc = 1.1 × 10−4 Ω cm2) than Pd/Ge/Au, and over a wider range of anneal temperature than Au/Zn/Au. The incorporation of the superlattice in the p-In0.47Ga0.53As/ InP structure resulted in Pd/Zn/Pd/Au contacts with pc of 3.2 × 10−5 Ω cm2 as-deposited and 7.5 × 10−6 Ω.cm2 after a 500 °C anneal. The presence of Pd/Zn in the metallization was shown as important in reducing pc. Significant intermixing of the metal layers and In0.47Ga0.53As occured at ≥ 350 °C, as revealed by Rutherford backscattering spectrometry.

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 Preparation and Characterization of Porous Ceramic Membranes for Micro-Filtration from Clay/CuZn Using Extrusion Methods

2018 ◽  
Vol 156 ◽  
pp. 08015 ◽  
Author(s):  
Muh Amin ◽  
Muhammad Subri
Keyword(s):  
Porous Ceramic ◽  
Ceramic Materials ◽  
Ceramic Membranes ◽  
Extrusion Process ◽  
X Ray Diffraction ◽  
Percentage Composition ◽  
X Ray ◽  
Ceramic Support ◽  
Fabrication And Characterization

In this study, fabrication and characterization of ceramic membranes preparation was carried out. Porous ceramic membranes were fabricated by extrusion process from different percentage composition of CuZn on (80 wt% Clay, 10 wt% TiO2, 5 wt% Carbon and 5 wt% PVA). The fabricated membranes were sintered at 900°C for 1 hour in an electrical box furnace with heating rate 1oC/min and holding time for 1 hour. Apparent density and porosity were determined by standar methods for ceramic materials. Phase composition of the ceramic support was established by X-Ray Diffraction analysis. SEM studies of the membranes added at different CuZn were carried out.

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