Ni-Based Ohmic Contacts to Silicon Carbide Examined by Electron Microscopy

2012 ◽  
Vol 186 ◽  
pp. 82-85 ◽  
Author(s):  
Marek Wzorek ◽  
Andrzej Czerwiński ◽  
Andrian V. Kuchuk ◽  
Jacek Ratajczak ◽  
Ania Piotrowska ◽  
...  

Ni/Si multilayer contact structures to 4H-SiC after subsequent annealing steps are investigated with electron microscopy methods. After high temperature annealing step, specific defects in the contact structures are observed. The influence of phase transformations during annealings on the morphology on the contacts is discussed and the explanation of formation mechanism of voids within contact layer is proposed.

Author(s):  
P. Roitman ◽  
B. Cordts ◽  
S. Visitserngtrakul ◽  
S.J. Krause

Synthesis of a thin, buried dielectric layer to form a silicon-on-insulator (SOI) material by high dose oxygen implantation (SIMOX – Separation by IMplanted Oxygen) is becoming an important technology due to the advent of high current (200 mA) oxygen implanters. Recently, reductions in defect densities from 109 cm−2 down to 107 cm−2 or less have been reported. They were achieved with a final high temperature annealing step (1300°C – 1400°C) in conjunction with: a) high temperature implantation or; b) channeling implantation or; c) multiple cycle implantation. However, the processes and conditions for reduction and elimination of precipitates and defects during high temperature annealing are not well understood. In this work we have studied the effect of annealing temperature on defect and precipitate reduction for SIMOX samples which were processed first with high temperature, high current implantation followed by high temperature annealing.


1990 ◽  
Vol 183 ◽  
Author(s):  
J. L. Batstone

AbstractMotion of ordered twin/matrix interfaces in films of silicon on sapphire occurs during high temperature annealing. This process is shown to be thermally activated and is analogous to grain boundary motion. Motion of amorphous/crystalline interfaces occurs during recrystallization of CoSi2 and NiSi2 from the amorphous phase. In-situ transmission electron microscopy has revealed details of the growth kinetics and interfacial roughness.


2005 ◽  
Vol 483-485 ◽  
pp. 489-492 ◽  
Author(s):  
P.G. Baranov ◽  
Ivan V. Ilyin ◽  
Marina V. Muzafarova ◽  
E.N. Mokhov ◽  
S.G. Konnikov

The high-temperature stable defect complexes in 6H-SiC crystals created by heavy neutron irradiation and following high-temperature annealing have been discovered by EPR. After annealing at 1500°C at least five new axially symmetric centers with the electron spin S = 1/2 and S = 1 were shown to arise in 6H-SiC crystals. The striking feature of all discovered centers is a strong hyperfine interaction with a great number (up to twelve) of equivalent host Si (C) atoms. Two models, a four-vacancy complex VSi-3VC, and a split-interstitial antisite (C2)Si or a pair of two antisites (C2)Si-SiC are discussed. There is a good probability that some of new centers could be related to the famous D1 and DII centers. After annealing at 2000°C the dc1-dc4 centers disappeared and a new triplet center labeled as N-V in the form of a silicon vacancy and a nitrogen atom in neighboring carbon substitutional position has been observed. The parameters of this center are similar to that for well-known N-V center in diamond.


2013 ◽  
Vol 740-742 ◽  
pp. 485-489 ◽  
Author(s):  
Wei Huang ◽  
Shao Hui Chang ◽  
Xue Chao Liu ◽  
Zheng Zheng Li ◽  
Tian Yu Zhou ◽  
...  

The near-SiC-interfaces of annealed Ni/SiC contacts were observed directly by high-resolution transmission electron microscopy (HRTEM). 1 nm native oxide layer was observed in the as-deposited contact interface. The native oxide layer cannot be removed at 650°C through rapid thermal annealing (RTA) and it was completely removed at 1000°C RTA. The residue of native oxide layer resulted in the Schottky characters. High temperature annealing (>950°C) not only removes the oxide layer in the near-SiC-interface, but also forms a well arranged flat Ni2Si/SiC interface, which contribute to the formation of ohmic behavior.


1998 ◽  
Vol 555 ◽  
Author(s):  
A. I. Il'Insky ◽  
A. S. Terletsky ◽  
E. W. Zozulya

AbstractMicrostructure of dispersion hardened composites (DC) Cu-Al2O3 prepared by simultaneous vacuum vapor condensation of Cu and A12O3 was studied by X-ray diffractometry and transmission electron microscopy methods. After high temperature annealing at 900°C for 2 hours the composites retain the submicrocrystalline structure and high level of strength -0.9 GPa. It has been found that strain hardening of vacuum deposited Cu-A12O3 composites takes place in three stages that is not typical for well-known composites of metallurgical origin.


1987 ◽  
Vol 107 ◽  
Author(s):  
A. Mogro-Campero ◽  
N. Lewis ◽  
S.A. Al-Marayati

AbstractEpitaxial silicon layers of 5¼m were grown on SIMOX wafers. The dislocation density decreases by more than an order of magnitude as a function of distance away from the buried oxide. Shallow pits (about 0.5 urn deep and several um wide) are observed on the epitaxial layer with a density of 1-2 mm2. Their density did not change with various processing variations. A search for the origin of the pits by transmission electron microscopy reveals that they may be associated with regions of irregularly thin and sometimes missing buried oxide, which appear after the usual high temperature SIMOX annealing step. These defective regions in the buried oxide appear to initiate twinned growth in the epitaxial silicon, and are associated with pits at the top epitaxial silicon surface.


2020 ◽  
Vol 303 ◽  
pp. 111-117
Author(s):  
E.L. Nikonenko ◽  
Natalya A. Popova ◽  
N.A. Koneva

The present study was conducted by transmission electron microscopy (TEM) in order to investigate the structure of multicomponent nickel-based alloy obtained by directional solidification and change in its phase composition at high-temperature annealing. All states of the alloy possessed monocrystalline structure with [001] orientation. The alloy under study contained other elements apart from Ni, such as: Al, Co, and also Mo, Cr, W, Ta, Re, and Ru. The alloy was investigated in three states after annealing for: 1) 118 h; 2) 372 h; 3) 1274 h at 1000°С. The basic phases that form the alloy were γ and γ′. In the state after annealing for 118 h Al6(Re,Ru) phase was observed in an insignificant amount. After longer high temperature annealing new phases occurred, such as σ-phase and δ-phase, Laves phase. The structures occurring during annealing can be classified into four types: 1) quasi-cuboids, 2) anisotropic stripe structures, 3) anisotropic structures of striped type with σ-phase separation, 4) structureless zones with large two-phase areas.


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